The roles of nitrogen species on graphene aerogel supported Cu-Zn as efficient catalysts for CO2 hydrogenation to methanol

Abstract

The nitrogen heteroatom has been recently doped into carbon materials such as carbon nanotubes and graphene for enhance the catalytic activity of CO2 hydrogenation to methanol. However, the role in each of the nitrogen species are not yet fully understood. In this work, the nitrogen has been doped to the graphene aerogel by using different nitrogen sources (i.e., ammonia, hydrazine hydrate, and urea) via a hydrothermal reduction method, and the role of each nitrogen species has been investigated. It is found that 15%CuZn loaded on nitrogen doped graphene aerogel catalyst using urea as a precursor provided the highest space-time yield of methanol (405.49 mg gcat−1 h−1). Remarkably, the increase of pyridinic nitrogen can greatly promote the catalytic performance and enhance the methanol production. This work is the first systematic study on the influent of nitrogen species doping on graphene aerogel support and also proves that pyridinic-N plays an important role to enhance the catalytic performance.