Surfactant PVA-Stabilized Co–Mo Nanocatalyst Supported by Graphene Oxide Sheets Toward the Hydrolytic Dehydrogenation of Ammonia Borane

Abstract

By adding surfactant polyvinyl alcohol (PVA) and controlling the preparation process, we successfully synthesized Co–Mo catalysts. For further improving the dispersion, reduced graphene oxide sheets as catalyst carrier were introduced to synthesize Co–Mo@rGO composite catalyst as highly efficient catalysts for hydrolytic dehydrogenation of ammonia borane. The introduction of Mo for preparing Co–Mo@rGO catalyst helped to form alloy catalyst with better structure, better dispersity and smaller particle size. When the molar ratio of Co and Mo was 0.75:0.25, the bimetallic composite catalyst exhibited superior activity with TOF value of 16.29[Formula: see text]mol[Formula: see text]. The activation energy of the reaction was calculated to be 43.72[Formula: see text]kJ[Formula: see text][Formula: see text]. Furthermore, the reusability tests reveal that waxberry-like Co–Mo still show good catalytic activity with 80.3% of their initial activity in five successive runs. The enhanced catalytic activities were due to the synergistic interaction between graphene sheets and waxberry-like Co–Mo NPs, which was beneficial to improve the dispersion and stability of bimetallic NPs. Also, ligand effects on the formation of waxberry-like structure and amorphous state further promoted the catalytic activity.