肼硼烷完全产氢用镍基非贵金属纳米复合催化材料体系的构建及性能研究

Hydrazine borane (N2H4BH3, HB) has been considered as a novel and promising hydrogen storage material for its high hydrogen content 15.3 wt%. Especially, a promising approach for complete hydrogen production from N2H4BH3 is by hydrolysis of the BH3 group and selective decomposition of the N2H4 moiety of N2H4BH3, corresponding to a theoretical gravimetric hydrogen storage capacity (GHSC) of 10.0 wt% for the system N2H4BH3-3H2O. The GHSC of N2H4BH3 is much higher than those of benchmark hydrogen storage systems NaBH4-4H2O (7.3 wt%) and NH3BH3-4H2O (5.9 wt%), and N2H4•H2O (8.0 wt%). In order to promote the practical application of HB as a hydrogen storage material, the development of highly efficient and low cost (noble-metal-free) catalyst for completely conversion of HB to H2 is crucial and challenging. Based on the molecular structure and physical/chemical properties of HB, this project will design and prepare the new Ni-based non-noble-metal catalysts using different synthesis method to complete catalytic hydrogen generation from HB. Therefore, we can obtain the chemical hydrogen storage material system with high storage gravimetric hydrogen density, low operating temperature, and controllable hydrogen generation. By investigating the hydrogen generation from HB using different catalysts, different amount of catalysts and HB, and different reaction temperature, the controllable hydrogen making method will be explored and the catalytic reaction kinetics will be made clear. Combined with the density functional theory calculations and experimental results, the structure-activity relationship and catalytic reaction mechanism of hydrogen generation from HB over the catalysts will be analyzed, which could provide the theoretical instruction and experimental evidence on the design and development of the cheap and efficient catalysts for hydrogen production.

肼硼烷（N2H4BH3）的含氢量高达15.4wt%，是一种颇具应用前景的储氢材料。特别是，通过水解其硼烷基和选择性裂解肼基实现完全产氢后，其对应的N2H4BH3-3H2O系统储氢容量达10.0wt%，远高于已知氢源系统NaBH4-4H2O（7.3wt%），NH3BH3-4H2O（5.9wt%）和N2H4•H2O（8.0wt%）。发展不含贵金属的廉价高效制氢催化剂是推动肼硼烷实用化的关键和难点。本项目拟采用不同的纳米材料制备方法，设计并合成新型镍基非贵金属纳米复合催化剂，完全催化肼硼烷产氢，获取具有高储氢密度、低操作温度、可控放氢的化学储氢材料系统。通过深入研究肼硼烷产氢动力学行为，探索新型化学储氢材料肼硼烷的可控放氢技术，揭示肼硼烷催化水解反应动力学规律。结合密度泛函理论计算和实验研究结果，分析催化剂的构效关系和催化反应机理，为新型廉价高效制氢催化剂的设计开发提供理论指导和实验依据。

肼硼烷（N2H4BH3）含氢量高达15.4wt%，易溶于水，物理化学性质稳定，是一种颇具应用前景的新型化学储氢材料。特别是，在合适的催化剂条件下，它有望通过硼烷基的水解和肼基分解来实现完全产氢，获得放氢量相对产氢系统可达10.0wt%，远超过美国能源部设定的储氢材料要求指标。对于肼硼烷催化完全产氢研究的关键在于催化剂的研制。本项目针对肼硼烷分子结构与物理化学性质的特点，设计合成了一系列镍基纳米复合催化材料，包括几种高效的非贵金属材料，催化肼硼烷实现完全产氢。发展了利用过渡金属氧化物MoO3-x和Cr2O3调控活性金属NiM（M = Pt, Rh, Pd, Ir, Cu）的电子结构、结晶度、尺寸和分散性的方法，实现了富电子、低结晶度/无定型、高分散和超细纳米粒子尺寸的融合，制备了协同增强催化活性的金属纳米催化剂。比如发展的非贵金属CuNiMo催化剂在肼硼烷制氢反应中的氢气选择性和活性大幅度提高，是第一例能实现肼硼烷完全产氢的非贵金属催化剂。此外，我们还发展了首例在室温下可催化肼硼烷完全产氢的非贵金属催化剂Raney Ni。发展了一锅反胶束法制备的蠕虫状Ni-CeO2@SiO2核壳纳米剂对肼硼烷产氢表现出较好的催化活性和循环性。发展了一种通过调控煅烧温度来调控介孔碳氮材料的碳氮含量，制得的一系列不同碳氮含量的介孔碳氮材料作为载体，担载NiPt合金纳米颗粒用于催化肼硼烷制氢。所制备的Ni60Pt40/MCN-800表现出最佳的催化活性和100%的氢气选择性，在室温下的氢气转化频率高达1111 h-1。发展了一种还原剂用量控制和碱辅助的还原策略，将金属纳米颗粒固载在MOF和La2O2CO3并调控其尺寸及空间排布。比如发展的低贵金属含量的Ni0.9Pt0.1@MIL-101对肼硼烷产氢呈现出优异的催化性能（1515.0 h-1）和非常好的循环使用性能。本项目完成了预期研究计划，达到了预期目标，Journal of Materials Chemistry A、ACS Applied Materials & Interfaces、Nano Research、Inorganic Chemistry等知名期刊发表了标注受本项目资助的期刊论文35篇；其中ESI高被引论文有3篇；授权国家发明专利3项；申请中国发明专利4项。负责人以第一完成人获江西省自然科学奖一等奖。