Synergy between metallic components of MoNi alloy for catalyzing highly efficient hydrogen storage of MgH2
Meng Chen, Yanhui Pu, Zhenyang Li, Gang Huang, Xiaofang Liu, Yao Lu, Wukui Tang, Li Xu, Shuangyu Liu, Ronghai Yu, Jianglan Shui
Abstract
Catalysts play a critical role in improving the hydrogen storage kinetics in Mg/MgH2 system. Exploring highly efficient catalysts and catalyst design principles are hot topics but challenging. The catalytic activity of metallic elements on dehydrogenation kinetics generally follows a sequence of Ti>Nb>Ni>V>Co>Mo. Herein, we report a highly efficient alloy catalyst composed of low-active elements of Mo and Ni (i.e. MoNi alloy) for MgH2 particles. MoNi alloy nanoparticles show excellent catalytic effect, even outperforming most advanced Ti-based catalysts. The synergy between Mo and Ni elements can promote the break of Mg-H bonds and the dissociation of hydrogen molecules, thus significantly improves the kinetics of Mg/MgH2 system. The MoNi-catalyzed Mg/MgH2 system can absorb and release 6.7 wt.% hydrogen within 60 s and 10 min at 300 °C, respectively, and exhibits excellent cycling stability and low-temperature hydrogen storage performance. This study provides a strategy for designing efficient catalysts for hydrogen storage materials using the synergy of metal elements.