Architecture engineering toward highly active Rh integrated porous carbon with diverse flexible channels for hydrogen evolution

Abstract

To overcome the sluggish kinetics for catalytic hydrolysis of ammonium borane (AB) to generate hydrogen, it is crucially important to design advanced catalysts with tertiary pore structures and substantial surface-exposed active sites. In this study, we report an architecture engineering strategy to construct nitrogen-rich porous carbon nanosheets with hollow worm-like nanowires (h-NCNWs) using low-cost/non-toxic and easily available graphitic carbon nitride as a self-sacrificing template and nitrogen source. The obtained h-NCNWs enable the uniform deposition of ultrafine Rh nanoparticles (Rh/h-NCNWs). The resultant Rh/h-NCNW catalyst exhibits an excellent hydrogen production performance for AB hydrolysis without any alkali promoters. Specifically, the Rh/h-NCNW catalyst with a low Rh loading of 2.12 wt% delivers much higher catalytic activity with a turnover frequency of 1234 min⁻¹. The hollow worm-like nanowires created in Rh/h-NCNWs can provide diverse flexible channels to facilitate the exposure of copious surface-active sites and mass transport for AB hydrolysis, thereby promoting hydrogen evolution rates. This study provides an efficient strategy to engineer the architecture of the catalyst support for upgrading Rh metal-catalyzed hydrogen evolution from AB hydrolysis.