多孔碳负载镍纳米颗粒的制备及催化氨硼烷水解制氢

合成了蜂窝状的分级多孔碳,并以多孔碳为载体通过浸渍-化学还原法制备碳载镍(Ni/C)作为催化氨硼烷水解制氢的催化剂。采用XRD、BET、SEM、Raman、TEM等手段对样品进行了表征并研究了Ni/C室温催化性能。结果显示,多孔碳比表面积高达737 m2·g-1,具有部分石墨化结构;负载的非晶态镍纳米颗粒平均粒径约为10 nm,均匀分布在碳基材。碳载镍对氨硼烷水解反应具有良好的催化活性,镍负载量为30wt%时催化性能最佳,298 K温度下放氢速率达到1 304.67 m L·min-1·g-1,活化能为29.1 k J·mol-1,并且具备一定的催化稳定性,表明Ni/C可作为一种廉价高效的催化剂应用于催化氨硼烷水解制氢。

Preparation of Porous Carbon-Supported Ni Nanoparticles for Catalytic Hydrogen Generation from Ammonia Borane Hydrolysis

Honeycomb-like hierarchical porous carbon was prepared and employed as substrate to support nickel nanparticles via an impregnation-chemical reduction method. The synthesized carbon-supported nickel (denoted as Ni/C) was used as catalysts for hydrogen generation from hydrolysis of ammonia borane (AB). Results of XRD, BET, SEM, Raman, and TEM measurements showed that the synthesized carbon possessed high specific surface area of 737 m²·g^-1 and partially graphited structure; the supported amorphous Ni nanoparticles had an average particle size of 10 nm and were uniformly dispersed on the porous carbon substrate. The synthesized Ni/C exhibited high catalytic activity towards the hydrolysis of AB. At hydrolysis temperature of 298 K, Ni/C with 30wt% Ni loading was the most active, resulting in a high hydrogen release rate of 1304.67 mL·min^-1·g^-1 and a low activation energy of 29.1 kJ·mol^-1. In addition, the Ni/C catalyst could be repeatedly utilized with respectable activity reservation for several times. The results indicate that Ni/C is a promising low-cost catalyst for hydrolytic dehydrogenation of AB.