Efficient catalytic oxidation of methyl mercaptan to sulfur dioxide with NiCuFe mixed metal oxides

Abstract

A series of mixed metal oxides (MMO) with different Ni/Cu molar ratios, using nickel–copper–iron layered double hydroxides (NiCuFe-LDHs) as precursors, were prepared by coprecipitation method. The effects of calcination temperature on the catalytic oxidation of CH 3 SH by NiCuFe were investigated. In this work, Various characterization methods including XRD, FTIR, XPS, H 2 -TPR were carried out to investigate the structural properties of NiCuFe. The experiment results showed that among all synthesized catalysts, Ni 2.7 Cu 0.3 Fe 1 catalysts synthesized at the calcination temperature of 350 °C showed excellent catalytic activity for the selectivity of SO 2 (100%) at reaction temperature 360 °C, and had good catalytic stability over long period of 10 h. Based on the analysis of the XPS and in situ FT-IR, it was apparent that CH 3 SO 3 H was the intermediate product of oxidation reaction and the carbon accumulation and sulfur poisoning on the surface of the catalyst were the main reasons for its deactivation. This study provides guidance for the design of catalysts for SVOCs removal and deepens the comprehension of the reaction mechanism of odorous gases oxidation. • Ni 2.7 Cu 0.3 Fe 1 -350 has high effect of deep oxidation of methyl mercaptan. • Ni 2.7 Cu 0.3 Fe 1 -350 has excellent methyl mercaptan removal effect within 10 h. • The introduction of active oxygen and proper alkalinity form a double synergistic promotion mechanism in the reaction system.