SiO2-mediated fabrication of hydrophilic biomass-carbon and its expediting effect on Rh nanoparticles catalyzed dehydrogenation of ammonia borane

Abstract

Carbon materials deriving from biomass wastes have become particularly attractive and are broadly in line with the concepts of green chemistry because of their cost efficiency and their properties as abundant natural resources. However, it still remains a big challenge to seek suitable synthetic strategies and effective approaches to regulate the size/surface dependent properties for preparing high catalytic performance of biomass-derived carbons. In this work, for the first time, we demonstrate that the silicon dioxide (SiO2) modified carbonaceous materials from inner layer of pomelo peel (IPPC-SiO2), which can act as an excellent support for small-size and well-dispersed Rh nanoparticles (NPs). The as-synthesized Rh/IPP-SiO2 catalyst performs excellently for catalytic ammonia borane dehydrogenation reactions. The turnover frequency (TOF) value of ammonia borane hydrolysis is 1295 mol H2 min−1 (mol Rh)-1 and the activation energy is 26.1 kJ mol−1, indicating that the catalytic efficiency of the resulting composites is superior to that of most noble-metal catalysts reported. Based on these experimental results, a proposed mechanistic analysis of the SiO2 regulating biomass carbon is presented as an effective support of Rh nanoparticles for optimizing catalytic ammonia borane dehydrogenation.