High Performance Ru-CNx/CeO2 Catalyst for Catalytic Wet Oxidation of N-Methyldiethanolamine in Water

Abstract

The synthesis of high performance catalysts for the catalytic wet oxidation (CWO) of N-methyldiethanolamine (MDEA) in water remains a challenge, and is a topic of considerable importance in relation to sustainability. In this paper, a Ru-CNx/CeO2 catalyst was synthesized through a modified impregnation process for the CWO of MDEA, exhibiting a high activity of 80% COD removal at 180 °C and 2.5 MPa. EPR, Raman, and XPS characterizations revealed that the CNx species facilitated the reduction in Ru4+ to Ru0 species and enhanced the Ru–Ce interaction to form a high-density Ru-O-Ce structure with Ce3+ sites, which strongly correlate to the generation of oxygen vacancies. The oxygen vacancies enabled the adsorption and activation of the oxygen, generating active species (h+, ·O2−, and ·OH) that effectively oxidized the MDEA during the catalytic reaction.