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Nano-nickel catalytic dehydrogenation of ammonia borane

Nano-nickel catalytic dehydrogenation of ammonia borane Mater Renew Sustain Energy (2014) 3:23 DOI 10.1007/s40243-014-0023-8 OR IGINAL PAPER • • Dileep Kumar H. A. Mangalvedekar S. K. Mahajan Received: 21 June 2013 / Accepted: 21 January 2014 / Published online: 7 February 2014 The Author(s) 2014. This article is published with open access at Springerlink.com Abstract The complex chemical hydride, ammonia bor- Introduction ane (NH BH , AB) is a hydrogen rich compound. It is a 3 3 promising hydrogen source for applications using proton Ammonia borane (NH BH , AB) is a promising hydrogen 3 3 exchange membrane fuel cells (PEMFCs) due to hydrogen source material due to its high hydrogen content content. It has reasonably lower operating temperatures (19.6 wt%). It is a white crystalline solid compound which compared with other solid-state hydriding materials. At was first synthesized and characterized by Shore and Parry present, AB is an expensive disposable source which in its [1] in the year 1955. The primary elements that make pure form releases 1 mol of hydrogen at around 110 C. ammonia borane are nitrogen, hydrogen and boron. The This temperature is much higher than the operating tem- elements nitrogen and hydrogen exist widely in the nature, perature of PEMFC (*80 C). At the operating tempera- e.g., in air and water [2]. Ammonia borane is a non-volatile tures of the fuel cell, the slow kinetics of pure AB is a material with appreciable degree of stability in air and deterrent which provides enough scope for experimenta- water under ambient conditions. It can prove out to be an tion. The paper is the result of experimental thermolysis energy carrier for low power applications using proton effort by using nano-nickel as a catalyst with pure AB. The exchange membrane fuel cell (PEMFC) at lower temper- neat and catalyzed AB isothermal decomposition and atures. Release of H from amino boranes is a difficult and kinetic behavior are illustrated through the experimental complex process. Efforts are made to study the phenome- results obtained under various conditions. The focus of non in the experimentation. The molecular description of experimentation is to increase the rate and extent of release NH BH indicates that it is a donor–acceptor adduct 3 3 of hydrogen at lower temperatures. The experimental formed as a result of the dative bond between a Lewis acid results indicated that the use of nickel as catalyst reduced (BH ) and a Lewis base (NH )[3]. The compound is a 3 3 the induction period with significant improvement in solid at room temperature primarily due to di-hydrogen hydrogen release compared with neat AB. bonding and dipole–dipole interactions. Ammonia borane and diammoniate of diborane (DADB) are chemically Keywords Ammonia borane  Nano-nickel  similar with varying stability characteristics. It may be Dehydrogenation  Thermolysis  Kinetics  Decomposition inferred that AB is more readily applicable than DADB to hydrogen storage for automotive use [4]. Hydrogen release studies Ammonia borane can release more than 2 mol of H with D. Kumar (&)  H. A. Mangalvedekar VJTI, Matunga (E), Mumbai 400019, MS, India heating to modest temperatures. The reactions of hydrogen e-mail: dknayak@vpmthane.org evolution are summarized in Table 1. The optimum thermal decomposition reaction of S. K. Mahajan ammonium borohydride, NH BH ? BN ? 4H occurs 4 4 2 Directorate of Technical Education, 3, Mahapalika Marg, by a four-step process with H yields of 24 wt%. This far Mumbai 400001, MS, India 123 Page 2 of 7 Mater Renew Sustain Energy (2014) 3:23 exceeds the US DOE set ambitious and stiff target which is for mechanical mixing. Neat AB sample fourier transform 9 wt% for the year 2015. However, this will not make it an infra-red (FTIR) analysis was done before dehydrogenation immediate option as many issues about its practical usage using Bruker Germany model 3000 Hyperion Microscope are yet to be addressed. The strict hydrogen purity with Vertex 80 FTIR imaging system at the Sophisticated requirements for fuel cell applications demand minimiza- Analytical Instrumentation Facility (SAIF) in IIT Bombay. tion of side reactions [6]. The possibility of toxic gaseous The neat AB sample and catalyst Ni sample are char- boranes in the evolved H is likely to affect the fuel cell acterized for XRD spectrum using XPERT-PRO diffrac- performance. Above 500 C, AB can be completely tometer system with Cu anode and K having wave length – range of 5.0214–99.9834. The decomposed to form boron nitride (BN). The residue BN is of 1.554060A, in the 2O TEM imaging of the both the samples was done using not preferred for regeneration due to high chemical and Philips TEM model CM200. thermal stability and hence ammonia borane is treated as a disposable source [7]. The main hurdle in hydrogen release The experiments of isothermal decomposition were is the slow kinetics at lower temperatures leading to long conducted in an indigenously developed Sievert’s type induction period [8, 9]. Neat AB thermally decomposes apparatus at 80, 100, 120, 140 and 160 C, with different initially at 70 C and reaches a maximum at 112 C with samples of AB and ABNi. The catalyzed sample was the observed melting of AB to yield 1 mol of H and the prepared by mechanical milling technique using nano- by-product is polyaminoborane (NH BH ) .[2, 10, 11]. nickel in 10 % quantity i.e., 2 mg of Ni for 20 mg of AB 2 2 n Use of catalyst is one of the methods explored by many before each experiment. The volume of the evolved gas researchers in the past to improve kinetics as well as with respect to time and pressure is recorded. The fine mix hydrogen release at lower temperatures. Yao et al. [12] turned into gray colour and is used to perform isothermal used lithium (Li) catalysis and mesoporous carbon (CMK- decomposition test at five different temperatures starting 3) for thermal decomposition which released over 7 wt% from 80 C. Each sample was loaded in a crucible of hydrogen at 60 C. Chen et al. [13] used Co- and Ni-based cylindrical shape within the reactor. By using different catalysts and observed a release of 1 mol of hydrogen at valves, sample holder is connected at separate instants to 59 C. Burrell et al. [14] used Pt-catalyzed hydrogen vacuum pump, hydrogen gas cylinder, and the apparatus. In release from AB with 4 wt% at 70 C. Kalidindi et al. [15] each set of experiment and monitoring, the sample holder used Cu and Ni nanoparticles and observed higher kinetics was evacuated and filled with hydrogen gas before finally and hydrogen release. Sun et al. [16] performed monodis- connecting to the measuring setup of apparatus. A ther- perse nickel particles catalysis in hydrolytic dehydrogena- mocouple is placed very close to the sample holder to tion of AB with the goal of preparation of non-noble metal measure the accurate temperature to which the sample is catalyst. Gangal et al. [8] used silicon nanoparticles as subjected. The temperature and pressure are recorded catalyst and noted substantial reduction in activation digitally at intervals of 1 min using a data logger. The energy and absence of induction period. Manners et al. [17] change in pressure of the apparatus was used to calculate reported metals catalysis using Rh, Pd, Ru that could de- the amount of hydrogen released in wt%. The FTIR ana- hydrogenate ammonia borane at lower temperatures. Baker lysis was performed before and after dehydrogenation for et al. [18] used Ni to develop unprecedented ability of each of the catalyzed sample to study the bond structures of hydrogen release from ammonia borane. Most of the above reaction products. works included the use of organic or inorganic solvents and hydrolysis method to obtain improvements in the perfor- mance. After reviewing the performance and experimental Results and discussion processes adopted by earlier works, we decided to use nickel in its nano form as catalyst which holds enough XRD and TEM of Ni samples promise to improve the dehydrogenation process. The goal of our work is to use the low cost and abundantly available The XRD pattern of the Ni sample shown in Fig. 1 mat- nickel, a non-noble metal catalyst to optimize the hydrogen ches with the ICSD 64989, JCPDS reference code:00-004- release from ammonia borane. 0850. The presence of sharp peaks in the spectrum indi- cates the crystalline nature of the sample. The average crystal size calculated for the dominant peak (111) using Experimental Scherrer’s is found to be 55 nm. Hence, it can be con- firmed that the Ni is nano-sized and the catalyst being Ammonia borane complex (97 % pure) purchased from used is nano-nickel. Aldrich was used as received. Nano-nickel purchased from The TEM images of Ni shown in Fig. 2 indicate nano Laboratory Chemical Co. was used in the required quantity particles of average size 40–65 nm. The diffraction rings 123 Mater Renew Sustain Energy (2014) 3:23 Page 3 of 7 indicate the crystalline nature of the material matching 6, 7, 8, 9. This helps to compare the pristine AB and cat- with the XRD pattern. alyzed AB thermolysis performances at each stage of The crystallite size found using the Scherrer’s formula is experiment. The amount of catalyst used is around 10 % of estimated to be 46 nm and the dominant peak (110) the mass of neat AB. Mechanical mixing ensures proper – value of 24.1831. appearing at the 2O dispersion of the catalyst with the base material to increase The XRD pattern of the AB sample shown in Fig. material surface area. It can be observed from Fig. 5 that 3 matches well with JCPDS reference no: 01-074-0894. In the ABNi dehydrogenation started with reduced induction AB, the presence of sharp peaks indicates crystalline nature period of 8 min compared to over 125 min for neat AB at of the sample. This is in well accordance with the details 80 C. The reduction in induction period may be due to reported in literature where it is mentioned that AB shows nickel particles assisting in breaking of di-hydrogen bonds. orthorhombic structure at lower temperatures. At higher than ambient temperatures, AB shows tetragonal structure [19]. The TEM image of the considered AB sample in Fig. 4 confirms the crystalline structure in the range 34–70 nm. Hence, it is found through XRD characterization and TEM imaging that both ammonia borane and nickel used are nano-sized crystalline structure materials. Isothermal decomposition Thermolysis is a method which requires heating with tem- perature control. The Sievert’s type apparatus is a setup which permits this type of test on small quantities of mate- rial. Apparatus is designed to deal with challenges associated with solid-state reactions at elevated temperatures for the dehydrogenation in various stages from the material. The isothermal decomposition of neat AB at lower temperatures is an extremely slow process with very long induction period. Strong chemical bond structure of neat AB is responsible for prolonged induction period and less hydrogen release at this temperature. The max release was Fig. 1 XRD of Ni sample achieved beyond 250 min which remained steady thereaf- ter. Considerable reduction in the induction period is observed when isothermal decomposition was performed at 100 and 120 C. Beyond induction period, 6–7 wt% gas is released. The literature provides the details of melting point of AB as 112–114 C and at this temperature 1 mol equivalent of gas is liberated [20]. During 120 C isothermal cycle, the hydrogen released is over 9 wt% which remains steady after 100 min with nominal induction period. The observations indicate that the increase in temperature decreases the induction period as well as expedites dehydrogenation process. The iso- thermal volumetric hydrogen release measurements pre- sented the features that the neat AB sample released first mole of hydrogen at 110 C and the second mole at 160 C, respectively, in agreement with past results, respectively [19]. Catalytic dehydrogenation The dehydrogenation results of AB and ABNi and sub- sequent characterization are indicated graphically in Fig. 5, Fig. 2 TEM of Nickel sample 123 Page 4 of 7 Mater Renew Sustain Energy (2014) 3:23 Fig. 5 The curve indicating the hydrogen release through isothermal decomposition of neat AB and catalyzed AB at 80 C Fig. 3 XRD of ammonia borane sample Fig. 6 The curve indicating the hydrogen release through isothermal decomposition of neat AB and catalyzed AB at 100 C Fig. 4 TEM of ammonia borane sample ABNi decomposition at 140 and 160 C also have negli- The ABNi maximum hydrogen release is 4.5 wt% which is gible induction period with substantial increase in the much higher compared to 3 wt% of neat AB at this tem- hydrogen gas release. The neat AB hydrogen release at perature. It was also noted that the catalyzed samples did these temperatures was in the range of 12 wt%, whereas not foam during dehydrogenation. catalyzed decomposition resulted in release of 13.5 wt%. The induction period and hydrogen release wt% values for various temperatures are summarized in Table 2. Transmittance spectrum of neat AB and Ni catalyzed It could be noted from Fig. 6 that the first mole of AB hydrogen is released at around 100 C. Figure 7 indicates that the second mole at 120 C in ABNi samples with very FTIR transmittance spectrum provides information about negligible induction period. Figures 8 and 9 show that the the chemical bonds in the sample under study [8]. The 123 Mater Renew Sustain Energy (2014) 3:23 Page 5 of 7 Fig. 9 The curve indicating the hydrogen release through isothermal decomposition of neat AB and catalyzed AB at 160 C Fig. 7 The curve indicating the hydrogen release through isothermal decomposition of neat AB and catalyzed AB at 120 C Transmittance spectrum of dehydrogenated catalyzed ABNi The FTIR analysis of catalyzed dehydrogenated sample solid residue after each experiment with 80, 100, 120, 140 and 160 C was performed to understand the effect of catalyst on chemical bond structures. The transmit- tance spectrum in each case is indicated in Fig. 12.The spectrum in (a)–(e) is almost identical with the broad- ening of peaks in the N–H stretch or B–H stretch which indicates the material decomposition and hydrogen release. The release of hydrogen in terms of wt% has showed improvement in comparison with neat AB with considerable reduction in the induction period. The sec- ond mole release in the experiment at 160 C is visible in the transmittance curve with the broadening of N–H and B–H stretch. The characteristic frequencies corresponding to N–H, -1 N–H and N–H near 3,200 cm go on broadening as 2 3 the decomposition temperature increases and finally they Fig. 8 The curve indicating the hydrogen release through isothermal almost disappear. The same phenomenon is observed for decomposition of neat AB and catalyzed AB at 140 C the frequency bands corresponding to B–H–B–H stretch -1 FTIR analysis of neat AB and Ni catalyzed AB was con- observed near 2,200 cm . Shifting and broadening of ducted before and after decomposition. the peaks corresponding to B–H torsion and bend in the -1 The FTIR of neat AB before and after decomposition is range 1,000–1,500 cm are also seen clearly in the shown in Fig. 10. The FTIR of ABNi before and after Fig. 12. -1 decomposition is shown in Fig. 11. It is observed that vari- The peak near 700 cm corresponding B–N also ous bonds are resembling in both the samples indicating the appears to be slightly affected. It can be inferred that the -1 -1 B–N bend at 700 cm , B–H torsion at 1,500 cm , B–H hydrogen attached to borane and nitrogen is getting dis- 2 2 -1 -1 bend at 1,300 cm , B–H, B–H stretch at 2,300 cm and sociated and the borane–nitrogen bond in its place, ruling -1 N–H,N–H , N–H stretch above 3,000 cm . This justifies out the possibility of formation of ammonia. 2 3 the use of catalyst in the catalyzed sample is just facilitating Broadening of peaks indicates the disruption of bonds the dehydrogenation process. resulting in the release of hydrogen. It is seen that the B–N 123 Page 6 of 7 Mater Renew Sustain Energy (2014) 3:23 Table 1 Decomposition reactions for a thermal chemical hydride [5] a b Decomposition reaction Storage density , wt% H Temperature , C Product NH BH ? NH BH ? H 6.1 \25 Ammonia borane 4 4 3 3 2 NH BH ? NH BH ?H 6.5 \120 Polyaminoborane 3 3 2 2 2 NH BH ? NHBH ? H 6.9 [120 Polyaminoborane 2 2 2 NHBH ? BN ? H 7.3 [500 Borane nitride/borazine Theoretical maximum Decomposition temperature Table 2 AB and ABNi hydrogen release statistics Temperature (C) Induction Maximum release Max wt% period in Min duration in Min AB ABNi AB ABNi AB ABNi 80 125 8 275 60 3 4.75 100 15 0 200 50 5.75 6.00 120 10 0 300 75 9.25 10.5 140 5 0 175 60 11 13.0 160 0 0 175 50 12 13.5 Fig. 11 FTIR curves for ABNi before and after decomposition at 80 C temperatures. With the rise in temperature, significant improvement in hydrogen release is observed at every stage with fast reaction kinetics and faster release of hydrogen. Conclusion XRD and TEM of Ni and AB confirmed the nano-sized crystalline structure of samples used. Isothermal decomposition of ABNi clearly indicated significant improvement in hydrogen release with reduced Fig. 10 FTIR curves for neat AB before and after decomposition at induction period compared to AB. 160 C The FTIR of neat and catalyzed AB is indicating no much difference in the transmittance characteristics. This helps in concluding that the presence of nickel as a catalyst bend is intact and has not got affected either due to catalysis or due to elevated temperatures. The non-forma- is just facilitating the dehydrogenation process. The FTIR of dehydrogenated sample indicates the tion of borazine is an indication that there are no unwanted reactions and by-products. release of hydrogen from various B–H and N–H bonds. The mechanical mixing of Ni with neat AB has resulted in The FTIR study has indicated that there is gradual release of the hydrogen gas as the bonds are getting considerable reduction in the induction time and affected and the reactions are taking place at lower improvement in hydrogen release rate. 123 Mater Renew Sustain Energy (2014) 3:23 Page 7 of 7 3. Weaver, J.R., Shore, S.G., Parry, R.W.: The dipole moment of ammonia–borane. J. Chem. Phys. 29, 1 (1958) 4. Karkamkar, A., Aardahl, C., Autrey, T.: Recent developments on hydrogen release from ammonia borane. Mater. Matters 2, 6–9 (2007) 5. Riis, T., Sandrock, G.: Hydrogen storage—gaps and priorities. HIA HCG Storage paper, 11 (2005) 6. Autrey, T., Gutowska, A., Li, L., Linehan, J., Gutowski, M.: Chemical hydrogen storage in nano-structured materials, control of hydrogen release and reactivity from ammonia borane com- plexes. J. Am. Chem. Soc. Div. Fuel Chem. 49(1), 150 (2004) 7. Diwan, M., Hwang, H.T., Al-Kukhun, A., Varma, A.: Hydrogen generation from noncatalytic hydrothermolysis of ammonia bor- ane for vehicle applications. AIChE J. 57, 259–264 (2011) 8. Gangal, A.C., Kale, P., Edla, R., Manna, J., Sharma, P.: Study of kinetics and thermal decomposition of ammonia borane in pre- sence of silicon nanoparticles. Int. J. Hydrog. Energy (2012). doi:10.1016/j.ijhydene.2012.01.017 9. Dileep, K., Mahajan, S.K., Mangalvedekar, H.A.: Hydrogen storage in amine borane complexes, pp. 1–5. ICFCHT, Kuala Lumpur (2011) 10. Stowe, A.C., Shaw, W.J., Linehan, J.C., Schmid, B., Autrey, T.: In situ solid state 11B MAS-NMR studies of the thermal decomposition of ammonia borane: mechanistic studies of the hydrogen release pathways from a solid state hydrogen storage material. Phys. Chem. Chem. Phys. 9, 1831 (2007) 11. Sit, V., Geanangel, R.A., Wendlandt, W.W.: The thermal disso- ciation of NH3BH3. Thermochim. Acta 113, 379 (1987) 12. Yao, X., Li, L., Sun, C., Du, A., Cheng, L., Zhu, Z., Yu, C., Zou, J., Smith, S.C., Wang, P., Cheng, H., Frost, R.L., Lu, G.Q.: Lithium-catalyzed dehydrogenation of ammonia borane within mesoporous carbon framework for chemical hydrogen storage. Adv. Funct. Mater. 19, 265–271 (2009) 13. Chen, P., He, T., Xiong, Z., Wu, G., Chu, H., Wu, C., Zhang, T.: Fig. 12 FTIR curves for dehydrogenated sample a 80 C b 100 C Nanosized Co- and Ni-catalyzed ammonia borane for hydrogen c 120 C d 140 C e 160 C storage. Chem. Mater. 21, 2315–2318 (2009) 14. Burrell, A.K., Shrestha, R.P., Diyabalanage, H.V.K., Semelsber- ger, T.A., Ott, K.C.: Catalytic dehydrogenation of ammonia The presence of BN bands in the FTIR of dehydroge- borane in non-aqueous medium. Int. J. Hydrog. Energy 34, 2616– -1 nated ABNi sample near 700 cm suggests that this band 2621 (2009) is not ruptured and the possibility of ammonia formation 15. Kalidindi, S.B., Jagirdar, B.R.: Hydrogen generation from ammonia borane using nanocatalysts. J Indian Inst. Sci. 90, 181– can be ruled out. 187 (2010) 16. Sun, S., Metin, O., Mazumder, V., Ozkar, S.: Monodisperse Acknowledgments The authors acknowledge the assistance of COE nickel nanoparticles and their catalysis in hydrolytic dehydroge- in CNDS Lab, VJTI Mumbai, SAIF Lab, IIT Bombay and Advanced nation of ammonia borane. J. Am. Chem. Soc. 132, 1468–1469 Materials Lab at V.P.M.’s Polytechnic, Thane for the facilities offered (2010) for the experimental investigation work. 17. Manners, I., Jaska, C.A., Temple, K., Lough, A.J.: Transition metal-catalyzed formation of boron–nitrogen bonds: catalytic Open Access This article is distributed under the terms of the dehydrocoupling of amine–borane adducts to form aminoboranes Creative Commons Attribution License which permits any use, dis- and borazines. J. Am. Chem. Soc. 125, 9424 (2003) tribution, and reproduction in any medium, provided the original 18. Baker, R.T., Keaton, R.J., Blacquiere, J.M.: Base metal catalyzed author(s) and the source are credited. dehydrogenation of ammonia–borane for chemical hydrogen storage. J. Am. Chem. Soc. 129, 1844 (2007) 19. Paolone, A., Palumbo, O., Rispoli, P., Cantelli, R., Autrey, T.: Hydrogen dynamics and characterization of the tetragonal-to- orthorhombic phase transformation in ammonia borane. J. Phy. References Chem. C 113, 5872–5878 (2009) 20. Hu, M.G., Geanangel, R.A., Wendlandt, W.: The thermal 1. Shore, S.G., Parry, R.W.: The crystalline compound ammonia decomposition of ammonia borane. Thermochim. Acta 23(2), borane. J. Am. Chem. Soc. 77, 6084 (1955) 249–255 (1978) 2. Peng, B., Chen, J.: Ammonia borane as an efficient and light- weight hydrogen storage medium. Energy Environ. Sci. 1, 479–483 (2008) http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Materials for Renewable and Sustainable Energy Springer Journals

Nano-nickel catalytic dehydrogenation of ammonia borane

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Material Science; Materials Science, general; Renewable and Green Energy; Renewable and Green Energy
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Abstract

Mater Renew Sustain Energy (2014) 3:23 DOI 10.1007/s40243-014-0023-8 OR IGINAL PAPER • • Dileep Kumar H. A. Mangalvedekar S. K. Mahajan Received: 21 June 2013 / Accepted: 21 January 2014 / Published online: 7 February 2014 The Author(s) 2014. This article is published with open access at Springerlink.com Abstract The complex chemical hydride, ammonia bor- Introduction ane (NH BH , AB) is a hydrogen rich compound. It is a 3 3 promising hydrogen source for applications using proton Ammonia borane (NH BH , AB) is a promising hydrogen 3 3 exchange membrane fuel cells (PEMFCs) due to hydrogen source material due to its high hydrogen content content. It has reasonably lower operating temperatures (19.6 wt%). It is a white crystalline solid compound which compared with other solid-state hydriding materials. At was first synthesized and characterized by Shore and Parry present, AB is an expensive disposable source which in its [1] in the year 1955. The primary elements that make pure form releases 1 mol of hydrogen at around 110 C. ammonia borane are nitrogen, hydrogen and boron. The This temperature is much higher than the operating tem- elements nitrogen and hydrogen exist widely in the nature, perature of PEMFC (*80 C). At the operating tempera- e.g., in air and water [2]. Ammonia borane is a non-volatile tures of the fuel cell, the slow kinetics of pure AB is a material with appreciable degree of stability in air and deterrent which provides enough scope for experimenta- water under ambient conditions. It can prove out to be an tion. The paper is the result of experimental thermolysis energy carrier for low power applications using proton effort by using nano-nickel as a catalyst with pure AB. The exchange membrane fuel cell (PEMFC) at lower temper- neat and catalyzed AB isothermal decomposition and atures. Release of H from amino boranes is a difficult and kinetic behavior are illustrated through the experimental complex process. Efforts are made to study the phenome- results obtained under various conditions. The focus of non in the experimentation. The molecular description of experimentation is to increase the rate and extent of release NH BH indicates that it is a donor–acceptor adduct 3 3 of hydrogen at lower temperatures. The experimental formed as a result of the dative bond between a Lewis acid results indicated that the use of nickel as catalyst reduced (BH ) and a Lewis base (NH )[3]. The compound is a 3 3 the induction period with significant improvement in solid at room temperature primarily due to di-hydrogen hydrogen release compared with neat AB. bonding and dipole–dipole interactions. Ammonia borane and diammoniate of diborane (DADB) are chemically Keywords Ammonia borane  Nano-nickel  similar with varying stability characteristics. It may be Dehydrogenation  Thermolysis  Kinetics  Decomposition inferred that AB is more readily applicable than DADB to hydrogen storage for automotive use [4]. Hydrogen release studies Ammonia borane can release more than 2 mol of H with D. Kumar (&)  H. A. Mangalvedekar VJTI, Matunga (E), Mumbai 400019, MS, India heating to modest temperatures. The reactions of hydrogen e-mail: dknayak@vpmthane.org evolution are summarized in Table 1. The optimum thermal decomposition reaction of S. K. Mahajan ammonium borohydride, NH BH ? BN ? 4H occurs 4 4 2 Directorate of Technical Education, 3, Mahapalika Marg, by a four-step process with H yields of 24 wt%. This far Mumbai 400001, MS, India 123 Page 2 of 7 Mater Renew Sustain Energy (2014) 3:23 exceeds the US DOE set ambitious and stiff target which is for mechanical mixing. Neat AB sample fourier transform 9 wt% for the year 2015. However, this will not make it an infra-red (FTIR) analysis was done before dehydrogenation immediate option as many issues about its practical usage using Bruker Germany model 3000 Hyperion Microscope are yet to be addressed. The strict hydrogen purity with Vertex 80 FTIR imaging system at the Sophisticated requirements for fuel cell applications demand minimiza- Analytical Instrumentation Facility (SAIF) in IIT Bombay. tion of side reactions [6]. The possibility of toxic gaseous The neat AB sample and catalyst Ni sample are char- boranes in the evolved H is likely to affect the fuel cell acterized for XRD spectrum using XPERT-PRO diffrac- performance. Above 500 C, AB can be completely tometer system with Cu anode and K having wave length – range of 5.0214–99.9834. The decomposed to form boron nitride (BN). The residue BN is of 1.554060A, in the 2O TEM imaging of the both the samples was done using not preferred for regeneration due to high chemical and Philips TEM model CM200. thermal stability and hence ammonia borane is treated as a disposable source [7]. The main hurdle in hydrogen release The experiments of isothermal decomposition were is the slow kinetics at lower temperatures leading to long conducted in an indigenously developed Sievert’s type induction period [8, 9]. Neat AB thermally decomposes apparatus at 80, 100, 120, 140 and 160 C, with different initially at 70 C and reaches a maximum at 112 C with samples of AB and ABNi. The catalyzed sample was the observed melting of AB to yield 1 mol of H and the prepared by mechanical milling technique using nano- by-product is polyaminoborane (NH BH ) .[2, 10, 11]. nickel in 10 % quantity i.e., 2 mg of Ni for 20 mg of AB 2 2 n Use of catalyst is one of the methods explored by many before each experiment. The volume of the evolved gas researchers in the past to improve kinetics as well as with respect to time and pressure is recorded. The fine mix hydrogen release at lower temperatures. Yao et al. [12] turned into gray colour and is used to perform isothermal used lithium (Li) catalysis and mesoporous carbon (CMK- decomposition test at five different temperatures starting 3) for thermal decomposition which released over 7 wt% from 80 C. Each sample was loaded in a crucible of hydrogen at 60 C. Chen et al. [13] used Co- and Ni-based cylindrical shape within the reactor. By using different catalysts and observed a release of 1 mol of hydrogen at valves, sample holder is connected at separate instants to 59 C. Burrell et al. [14] used Pt-catalyzed hydrogen vacuum pump, hydrogen gas cylinder, and the apparatus. In release from AB with 4 wt% at 70 C. Kalidindi et al. [15] each set of experiment and monitoring, the sample holder used Cu and Ni nanoparticles and observed higher kinetics was evacuated and filled with hydrogen gas before finally and hydrogen release. Sun et al. [16] performed monodis- connecting to the measuring setup of apparatus. A ther- perse nickel particles catalysis in hydrolytic dehydrogena- mocouple is placed very close to the sample holder to tion of AB with the goal of preparation of non-noble metal measure the accurate temperature to which the sample is catalyst. Gangal et al. [8] used silicon nanoparticles as subjected. The temperature and pressure are recorded catalyst and noted substantial reduction in activation digitally at intervals of 1 min using a data logger. The energy and absence of induction period. Manners et al. [17] change in pressure of the apparatus was used to calculate reported metals catalysis using Rh, Pd, Ru that could de- the amount of hydrogen released in wt%. The FTIR ana- hydrogenate ammonia borane at lower temperatures. Baker lysis was performed before and after dehydrogenation for et al. [18] used Ni to develop unprecedented ability of each of the catalyzed sample to study the bond structures of hydrogen release from ammonia borane. Most of the above reaction products. works included the use of organic or inorganic solvents and hydrolysis method to obtain improvements in the perfor- mance. After reviewing the performance and experimental Results and discussion processes adopted by earlier works, we decided to use nickel in its nano form as catalyst which holds enough XRD and TEM of Ni samples promise to improve the dehydrogenation process. The goal of our work is to use the low cost and abundantly available The XRD pattern of the Ni sample shown in Fig. 1 mat- nickel, a non-noble metal catalyst to optimize the hydrogen ches with the ICSD 64989, JCPDS reference code:00-004- release from ammonia borane. 0850. The presence of sharp peaks in the spectrum indi- cates the crystalline nature of the sample. The average crystal size calculated for the dominant peak (111) using Experimental Scherrer’s is found to be 55 nm. Hence, it can be con- firmed that the Ni is nano-sized and the catalyst being Ammonia borane complex (97 % pure) purchased from used is nano-nickel. Aldrich was used as received. Nano-nickel purchased from The TEM images of Ni shown in Fig. 2 indicate nano Laboratory Chemical Co. was used in the required quantity particles of average size 40–65 nm. The diffraction rings 123 Mater Renew Sustain Energy (2014) 3:23 Page 3 of 7 indicate the crystalline nature of the material matching 6, 7, 8, 9. This helps to compare the pristine AB and cat- with the XRD pattern. alyzed AB thermolysis performances at each stage of The crystallite size found using the Scherrer’s formula is experiment. The amount of catalyst used is around 10 % of estimated to be 46 nm and the dominant peak (110) the mass of neat AB. Mechanical mixing ensures proper – value of 24.1831. appearing at the 2O dispersion of the catalyst with the base material to increase The XRD pattern of the AB sample shown in Fig. material surface area. It can be observed from Fig. 5 that 3 matches well with JCPDS reference no: 01-074-0894. In the ABNi dehydrogenation started with reduced induction AB, the presence of sharp peaks indicates crystalline nature period of 8 min compared to over 125 min for neat AB at of the sample. This is in well accordance with the details 80 C. The reduction in induction period may be due to reported in literature where it is mentioned that AB shows nickel particles assisting in breaking of di-hydrogen bonds. orthorhombic structure at lower temperatures. At higher than ambient temperatures, AB shows tetragonal structure [19]. The TEM image of the considered AB sample in Fig. 4 confirms the crystalline structure in the range 34–70 nm. Hence, it is found through XRD characterization and TEM imaging that both ammonia borane and nickel used are nano-sized crystalline structure materials. Isothermal decomposition Thermolysis is a method which requires heating with tem- perature control. The Sievert’s type apparatus is a setup which permits this type of test on small quantities of mate- rial. Apparatus is designed to deal with challenges associated with solid-state reactions at elevated temperatures for the dehydrogenation in various stages from the material. The isothermal decomposition of neat AB at lower temperatures is an extremely slow process with very long induction period. Strong chemical bond structure of neat AB is responsible for prolonged induction period and less hydrogen release at this temperature. The max release was Fig. 1 XRD of Ni sample achieved beyond 250 min which remained steady thereaf- ter. Considerable reduction in the induction period is observed when isothermal decomposition was performed at 100 and 120 C. Beyond induction period, 6–7 wt% gas is released. The literature provides the details of melting point of AB as 112–114 C and at this temperature 1 mol equivalent of gas is liberated [20]. During 120 C isothermal cycle, the hydrogen released is over 9 wt% which remains steady after 100 min with nominal induction period. The observations indicate that the increase in temperature decreases the induction period as well as expedites dehydrogenation process. The iso- thermal volumetric hydrogen release measurements pre- sented the features that the neat AB sample released first mole of hydrogen at 110 C and the second mole at 160 C, respectively, in agreement with past results, respectively [19]. Catalytic dehydrogenation The dehydrogenation results of AB and ABNi and sub- sequent characterization are indicated graphically in Fig. 5, Fig. 2 TEM of Nickel sample 123 Page 4 of 7 Mater Renew Sustain Energy (2014) 3:23 Fig. 5 The curve indicating the hydrogen release through isothermal decomposition of neat AB and catalyzed AB at 80 C Fig. 3 XRD of ammonia borane sample Fig. 6 The curve indicating the hydrogen release through isothermal decomposition of neat AB and catalyzed AB at 100 C Fig. 4 TEM of ammonia borane sample ABNi decomposition at 140 and 160 C also have negli- The ABNi maximum hydrogen release is 4.5 wt% which is gible induction period with substantial increase in the much higher compared to 3 wt% of neat AB at this tem- hydrogen gas release. The neat AB hydrogen release at perature. It was also noted that the catalyzed samples did these temperatures was in the range of 12 wt%, whereas not foam during dehydrogenation. catalyzed decomposition resulted in release of 13.5 wt%. The induction period and hydrogen release wt% values for various temperatures are summarized in Table 2. Transmittance spectrum of neat AB and Ni catalyzed It could be noted from Fig. 6 that the first mole of AB hydrogen is released at around 100 C. Figure 7 indicates that the second mole at 120 C in ABNi samples with very FTIR transmittance spectrum provides information about negligible induction period. Figures 8 and 9 show that the the chemical bonds in the sample under study [8]. The 123 Mater Renew Sustain Energy (2014) 3:23 Page 5 of 7 Fig. 9 The curve indicating the hydrogen release through isothermal decomposition of neat AB and catalyzed AB at 160 C Fig. 7 The curve indicating the hydrogen release through isothermal decomposition of neat AB and catalyzed AB at 120 C Transmittance spectrum of dehydrogenated catalyzed ABNi The FTIR analysis of catalyzed dehydrogenated sample solid residue after each experiment with 80, 100, 120, 140 and 160 C was performed to understand the effect of catalyst on chemical bond structures. The transmit- tance spectrum in each case is indicated in Fig. 12.The spectrum in (a)–(e) is almost identical with the broad- ening of peaks in the N–H stretch or B–H stretch which indicates the material decomposition and hydrogen release. The release of hydrogen in terms of wt% has showed improvement in comparison with neat AB with considerable reduction in the induction period. The sec- ond mole release in the experiment at 160 C is visible in the transmittance curve with the broadening of N–H and B–H stretch. The characteristic frequencies corresponding to N–H, -1 N–H and N–H near 3,200 cm go on broadening as 2 3 the decomposition temperature increases and finally they Fig. 8 The curve indicating the hydrogen release through isothermal almost disappear. The same phenomenon is observed for decomposition of neat AB and catalyzed AB at 140 C the frequency bands corresponding to B–H–B–H stretch -1 FTIR analysis of neat AB and Ni catalyzed AB was con- observed near 2,200 cm . Shifting and broadening of ducted before and after decomposition. the peaks corresponding to B–H torsion and bend in the -1 The FTIR of neat AB before and after decomposition is range 1,000–1,500 cm are also seen clearly in the shown in Fig. 10. The FTIR of ABNi before and after Fig. 12. -1 decomposition is shown in Fig. 11. It is observed that vari- The peak near 700 cm corresponding B–N also ous bonds are resembling in both the samples indicating the appears to be slightly affected. It can be inferred that the -1 -1 B–N bend at 700 cm , B–H torsion at 1,500 cm , B–H hydrogen attached to borane and nitrogen is getting dis- 2 2 -1 -1 bend at 1,300 cm , B–H, B–H stretch at 2,300 cm and sociated and the borane–nitrogen bond in its place, ruling -1 N–H,N–H , N–H stretch above 3,000 cm . This justifies out the possibility of formation of ammonia. 2 3 the use of catalyst in the catalyzed sample is just facilitating Broadening of peaks indicates the disruption of bonds the dehydrogenation process. resulting in the release of hydrogen. It is seen that the B–N 123 Page 6 of 7 Mater Renew Sustain Energy (2014) 3:23 Table 1 Decomposition reactions for a thermal chemical hydride [5] a b Decomposition reaction Storage density , wt% H Temperature , C Product NH BH ? NH BH ? H 6.1 \25 Ammonia borane 4 4 3 3 2 NH BH ? NH BH ?H 6.5 \120 Polyaminoborane 3 3 2 2 2 NH BH ? NHBH ? H 6.9 [120 Polyaminoborane 2 2 2 NHBH ? BN ? H 7.3 [500 Borane nitride/borazine Theoretical maximum Decomposition temperature Table 2 AB and ABNi hydrogen release statistics Temperature (C) Induction Maximum release Max wt% period in Min duration in Min AB ABNi AB ABNi AB ABNi 80 125 8 275 60 3 4.75 100 15 0 200 50 5.75 6.00 120 10 0 300 75 9.25 10.5 140 5 0 175 60 11 13.0 160 0 0 175 50 12 13.5 Fig. 11 FTIR curves for ABNi before and after decomposition at 80 C temperatures. With the rise in temperature, significant improvement in hydrogen release is observed at every stage with fast reaction kinetics and faster release of hydrogen. Conclusion XRD and TEM of Ni and AB confirmed the nano-sized crystalline structure of samples used. Isothermal decomposition of ABNi clearly indicated significant improvement in hydrogen release with reduced Fig. 10 FTIR curves for neat AB before and after decomposition at induction period compared to AB. 160 C The FTIR of neat and catalyzed AB is indicating no much difference in the transmittance characteristics. This helps in concluding that the presence of nickel as a catalyst bend is intact and has not got affected either due to catalysis or due to elevated temperatures. The non-forma- is just facilitating the dehydrogenation process. The FTIR of dehydrogenated sample indicates the tion of borazine is an indication that there are no unwanted reactions and by-products. release of hydrogen from various B–H and N–H bonds. The mechanical mixing of Ni with neat AB has resulted in The FTIR study has indicated that there is gradual release of the hydrogen gas as the bonds are getting considerable reduction in the induction time and affected and the reactions are taking place at lower improvement in hydrogen release rate. 123 Mater Renew Sustain Energy (2014) 3:23 Page 7 of 7 3. Weaver, J.R., Shore, S.G., Parry, R.W.: The dipole moment of ammonia–borane. J. Chem. Phys. 29, 1 (1958) 4. Karkamkar, A., Aardahl, C., Autrey, T.: Recent developments on hydrogen release from ammonia borane. Mater. Matters 2, 6–9 (2007) 5. Riis, T., Sandrock, G.: Hydrogen storage—gaps and priorities. HIA HCG Storage paper, 11 (2005) 6. Autrey, T., Gutowska, A., Li, L., Linehan, J., Gutowski, M.: Chemical hydrogen storage in nano-structured materials, control of hydrogen release and reactivity from ammonia borane com- plexes. J. Am. Chem. Soc. Div. Fuel Chem. 49(1), 150 (2004) 7. Diwan, M., Hwang, H.T., Al-Kukhun, A., Varma, A.: Hydrogen generation from noncatalytic hydrothermolysis of ammonia bor- ane for vehicle applications. AIChE J. 57, 259–264 (2011) 8. Gangal, A.C., Kale, P., Edla, R., Manna, J., Sharma, P.: Study of kinetics and thermal decomposition of ammonia borane in pre- sence of silicon nanoparticles. Int. J. Hydrog. Energy (2012). doi:10.1016/j.ijhydene.2012.01.017 9. Dileep, K., Mahajan, S.K., Mangalvedekar, H.A.: Hydrogen storage in amine borane complexes, pp. 1–5. ICFCHT, Kuala Lumpur (2011) 10. Stowe, A.C., Shaw, W.J., Linehan, J.C., Schmid, B., Autrey, T.: In situ solid state 11B MAS-NMR studies of the thermal decomposition of ammonia borane: mechanistic studies of the hydrogen release pathways from a solid state hydrogen storage material. Phys. Chem. Chem. Phys. 9, 1831 (2007) 11. Sit, V., Geanangel, R.A., Wendlandt, W.W.: The thermal disso- ciation of NH3BH3. Thermochim. Acta 113, 379 (1987) 12. Yao, X., Li, L., Sun, C., Du, A., Cheng, L., Zhu, Z., Yu, C., Zou, J., Smith, S.C., Wang, P., Cheng, H., Frost, R.L., Lu, G.Q.: Lithium-catalyzed dehydrogenation of ammonia borane within mesoporous carbon framework for chemical hydrogen storage. Adv. Funct. Mater. 19, 265–271 (2009) 13. Chen, P., He, T., Xiong, Z., Wu, G., Chu, H., Wu, C., Zhang, T.: Fig. 12 FTIR curves for dehydrogenated sample a 80 C b 100 C Nanosized Co- and Ni-catalyzed ammonia borane for hydrogen c 120 C d 140 C e 160 C storage. Chem. Mater. 21, 2315–2318 (2009) 14. Burrell, A.K., Shrestha, R.P., Diyabalanage, H.V.K., Semelsber- ger, T.A., Ott, K.C.: Catalytic dehydrogenation of ammonia The presence of BN bands in the FTIR of dehydroge- borane in non-aqueous medium. Int. J. Hydrog. Energy 34, 2616– -1 nated ABNi sample near 700 cm suggests that this band 2621 (2009) is not ruptured and the possibility of ammonia formation 15. Kalidindi, S.B., Jagirdar, B.R.: Hydrogen generation from ammonia borane using nanocatalysts. J Indian Inst. Sci. 90, 181– can be ruled out. 187 (2010) 16. Sun, S., Metin, O., Mazumder, V., Ozkar, S.: Monodisperse Acknowledgments The authors acknowledge the assistance of COE nickel nanoparticles and their catalysis in hydrolytic dehydroge- in CNDS Lab, VJTI Mumbai, SAIF Lab, IIT Bombay and Advanced nation of ammonia borane. J. Am. Chem. Soc. 132, 1468–1469 Materials Lab at V.P.M.’s Polytechnic, Thane for the facilities offered (2010) for the experimental investigation work. 17. Manners, I., Jaska, C.A., Temple, K., Lough, A.J.: Transition metal-catalyzed formation of boron–nitrogen bonds: catalytic Open Access This article is distributed under the terms of the dehydrocoupling of amine–borane adducts to form aminoboranes Creative Commons Attribution License which permits any use, dis- and borazines. J. Am. Chem. Soc. 125, 9424 (2003) tribution, and reproduction in any medium, provided the original 18. Baker, R.T., Keaton, R.J., Blacquiere, J.M.: Base metal catalyzed author(s) and the source are credited. dehydrogenation of ammonia–borane for chemical hydrogen storage. J. Am. Chem. Soc. 129, 1844 (2007) 19. Paolone, A., Palumbo, O., Rispoli, P., Cantelli, R., Autrey, T.: Hydrogen dynamics and characterization of the tetragonal-to- orthorhombic phase transformation in ammonia borane. J. Phy. References Chem. C 113, 5872–5878 (2009) 20. Hu, M.G., Geanangel, R.A., Wendlandt, W.: The thermal 1. Shore, S.G., Parry, R.W.: The crystalline compound ammonia decomposition of ammonia borane. Thermochim. Acta 23(2), borane. J. Am. Chem. Soc. 77, 6084 (1955) 249–255 (1978) 2. Peng, B., Chen, J.: Ammonia borane as an efficient and light- weight hydrogen storage medium. Energy Environ. Sci. 1, 479–483 (2008)

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Materials for Renewable and Sustainable EnergySpringer Journals

Published: Feb 7, 2014

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