Bifunctional Ru-Cluster-Decorated Co3 B-Co(OH)2 Hybrid Catalyst Synergistically Promotes NaBH4 Hydrolysis and Water Splitting.

ABSTRACT

Developing a highly efficient bifunctional catalyst for hydrolysis of metal hydrides and spontaneous hydrogen evolution reaction (HER) is essential for substituting conventional fuels for H2 production. Herein, Ru-cluster-modified Co3 B-Co(OH)2 supported on nickel foam (Ru/Co3 B-Co(OH)2 @NF) is constructed by electroless deposition, calcination and chemical reduction. The catalyst exhibits an excellent hydrogen generation rate (HGR) of 4989 mL min-1 g c a t a l y s t - 1 ${{{\rm g}}_{catalyst}^{-1}}$ and good reusability, superior to most previously reported catalysts. Besides, Ru/Co3 B-Co(OH)2 @NF displays a prominent hydrogen evolution reaction catalytic capability with a low overpotential of 153.0 mV at 100 mA cm-2 (50.5 mV at 10 mA cm-2 ), a small Tafel slope of 40.0 mV dec-1 and long-term stability (100 h@10 mA cm-2 ) in 1.0 M KOH. The excellent catalytic H2 generation capacity benefits from the rapid charge transfer promoted by metallic Co3 B, the synergistic catalytic effect of Co3 B-Co(OH)2 and Ru clusters, and the unique composite structure favorable for solute transport and gas emission.