Ultrafast, dry microwave-assisted surface property modulations to boost carbon stabilized Ru nanocatalyst for catalytic hydrogen evolution

Abstract

Developing a facile, ultrafast, and solid-state strategy to modulate the surface chemistry and textural properties of carbon materials and thereby tune the surface sites of metal nanoparticles (NPs) anchored on themselves is one of the most challenging work. Herein, we develop a simple, rapid but efficient microwave-assisted solid-state strategy to modify carbon black (CB) with rich oxygenated groups, defects, and tunable textural properties. The simple and ultrafast treatment in a household microwave oven for only 10 s not only introduces abundant oxygenated groups and defects but also considerably adjusts the textural properties of OCB, which are beneficial for obtaining uniformly dispersed Ru nanoclusters (2.0 nm in diameter). The achieved Ru/OCB reveals a considerable activity improvement in catalytic hydrolysis of ammonia borane (AB) with turnover frequencies of 602 min−1 in aqueous solution and 1240 min−1 in alkaline solution, surpassing the Ru/CB and many reported Ru-based catalysts. Kinetic isotope effect measurement indicates that the activation of O–H bond in H2O is the rate-determining step toward AB hydrolysis. This study offers an ultrafast but efficient strategy to modify carbon materials as catalyst supports.