Metal-organic-framework derived controllable synthesis of mesoporous copper-cerium oxide composite catalysts for the preferential oxidation of carbon monoxide

Abstract

Among currently studied catalysts, CuO-CeO2 based materials hold the greatest promise for the preferential oxidation of CO (CO-PROX). Recently, many efforts have been concentrated on developing the original nanostructures inherited from metal-organic-frameworks (MOFs), which are considered to be excellent sacrificial templates or precursors to achieve metal oxide (or metal) nanoparticles with unique structure. In this paper, we synthesized CuO-CeO2 catalysts using an efficient and general strategy derived from CuxCe1−x-BTC MOFs after high temperature treatment. The as-prepared CuO-CeO2 catalysts display variable morphologies, crystal structures, and specific surface areas based on different ratios of Cu/Ce and calcination temperature. The catalytic performance shows that all CuO-CeO2 composite catalysts derived from the CuxCe1−x-BTC MOFs via heat treatment exhibit excellent catalytic performance for the CO-PROX reaction, and the Cu0.3Ce0.7O2 is the most active catalyst obtained under high calcination temperature at 650 °C for 4 h, demonstrating that the increase of Cu content and high temperature treatment can create more highly dispersed CuO clusters, which is in favor of the CO-PROX reaction. Meanwhile, the in-situ DRIFTS results show that the Cu0.3Ce0.7O2 catalyst displays the super CO adsorption capability, which induces the difference of catalytic performance for the CO-PROX reaction.