Maximizing hydrogen production by AB hydrolysis with Pt@cobalt oxide/N,O-rich carbon and alkaline ultrasonic irradiation

Abstract

Non-precious metal oxide/carbon hybrids have been identified as promising platforms to stabilize precious metals for ammonia borane (AB) hydrolysis to produce hydrogen, whereas their facile and environmental-friendly synthesis remains challenging. In this study, we report the sustainable one-step synthesis of nitrogen-doped carbon skeleton stabilized Co₃O₄ (Co₃O₄/NC) by direct pyrolysis of ethylenediaminetetraacetic acid disodium cobalt without any activators and doping agents. Due to the structural features of the Co₃O₄/NC architecture, subsize Pt NPs are uniformly distributed on the Co₃O₄/NC matrix (Pt@Co₃O₄/NC), which can be used as ultrahigh active and reusable catalysts for AB hydrolysis to produce hydrogen under ultrasonic irradiation. Typically, 0.50 wt%Pt@Co₃O₄/NC exhibits extraordinary catalytic activities with ultrahigh turnover frequencies of 2867/6809 min⁻¹ at 298 K in aqueous/basic solutions, respectively. The catalyst possesses excellent durability with 85% retaining the activity of the initial one after ten cycles. The highly dispersed subsize Pt NPs on the nanoporous structured Co₃O₄/NC with strong electronic metal–support interaction facilitate the oxidative cleavage of O–H bonds in H₂O molecules and thereby considerably boost the activity toward AB hydrolysis. This study provides a useful and sustainable strategy to construct highly active and reusable catalysts toward AB hydrolysis.