Enhanced catalytic performance of RuNi alloy nanoclusters toward hydrolytic dehydrogenation of NH3BH3

Abstract

Developing efficient and economical catalysts for ammonia borane (AB, NH3BH3) hydrolysis is of great significance in hydrogen generation. In this article, we support RuM (M = Fe, Co, Ni, Cu) alloys on graphene-doped porous g-C3N4 (named as g-C3N4-rGO) through an adsorption-chemical reduction procedure. Specifically, the Ru0.8Ni0.2 nanoclusters (NCs)-based heterogeneous catalysts exhibit higher catalytic activity toward the hydrolytic dehydrogenation of AB than the others. Catalyzed by Ru0.8Ni0.2/g-C3N4-rGO, the turnover frequency (TOF) reaches 905.0 min−1 in alkaline solution at 303 K, and the apparent activation energy (Ea) lowers to 27.2 kJ mol−1. The outstanding catalytic performance are originated from the highly dispersed RuNi NCs with a mean size of 1.40 nm, the fascinating alloy effect, as well as the unique geometric structure and heteroatomic groups of the g-C3N4-rGO composites. DFT calculation results further confirm that the alloy effect enhances the dissociation of H2O and hydrogen formation in AB hydrolysis, thus accelerating reaction rate. The facile fabrication strategy, reasonable cost-efficiency and exciting catalytic behavior endow the optimal catalysts promising potential in the field of hydrogen energy.