Graphitic carbon nitride-supported cobalt oxides as a potential catalyst for decomposition of N2O

Abstract

A material of graphitic carbon nitride-supported cobalt oxides (Co3O4/g-CN) was synthesized via a facile and cost-effective impregnation route as a high-performance catalyst for decomposition of N2O. For comparison, bare Co3O4 and other Co3O4 catalysts supported on activated carbon (AC) and γ-Al2O3 (Co3O4-A, Co3O4/AC, and Co3O4/γ-Al2O3, respectively) were also prepared. While g-CN was found to be active in the decomposition of N2O, AC and γ-Al2O3 were inert to this reaction. Co3O4/g-CN showed superior catalytic activity than the other catalysts, and concurrently exhibited much higher specific activity compared to Co3O4-A. The experimental results revealed that all examined catalysts had the spinel structure. The Co species could incorporate into the g-CN matrix/layers and bond to the g-CN matrix through Co-N coordination bonds. The excellent performance of Co3O4/g-CN was attributed to the high surface Co2+ content, massive surface oxygen species, facile electrons transfer from the catalyst to N2O domains, and the synergistic coupling effects among active species such as Co3+/Co2+ redox couple, Co-N, and nitrogen sites. The active Co3O4/g-CN catalyst additional activity tests were conducted with N2O gas contaminated with H2O, O2, or NO.