Cube CoCu-ZIF derived Ru/Co2.28Cu0.72O4/C7.5 for superb H2 production: Morphology and steam oxidation induced charge transfer

Considering the pursuit of clean living environment and the relatively low price of Ru, it is definitely desired to develop effective strategies to improve the H2 evolution performance from ammonia borane (AB) hydrolysis over Ru based catalysts. Herein, rhombic dodecahedron, truncated rhombic dodecahedron and cube bimetal CoCu-ZIFs were constructed through CTAB controlled facet engineering. MOF-derived Co2.28Cu0.72O4/C, with characteristics of generally inherited CoCu-ZIFs morphology, regulable hierarchical pores as well as in-situ N doping, were formed through straightforward pyrolysis in tubular furnace and nitric acid vapor oxidation. After Ru loading, Ru/Co2.28Cu0.72O4/C dual-active-sites (dual-active-sites referred to spinel Co2.28Cu0.72O4 and Ru NPs) catalyst was used in AB hydrolysis. Unprecedented 2020 min−1 TOF in H2 production capability were acquired with Ru/Co2.28Cu0.72O4/C7.5. The superior behavior was related to mass transfer promotion with nitric acid vapor oxidation assisted hierarchical mesoporous structure construction, the charge transfer improvement from spinel to Ru NPs with the oxygen vacancies introduction, and the morphology engineering with CTAB in dual-active-sites catalysts.