Preparation of MnO2 decorated Co3Fe1Ox powder/monolithic catalyst with improved catalytic activity for toluene oxidation

Abstract

In this paper, KMnO4 was used to pre-treat Co3Fe-layered double hydroxides (LDH) precursor to prepare MnO2 decorated Co3Fe1Ox catalyst. The toluene oxidation performance of the catalyst was investigated systematically. The optimized 0.1MnCF-LDO catalyst exhibited the best catalytic performance, and the temperatures of 50% and 90% toluene conversion (T50 and T90) were 218 and 243°C, respectively. The apparent activation energy (Ea) was 31.6 kJ/mol. The characterization results showed that the pre-redox reaction by KMnO4 could increase the specific surface area, Co3+ species amount and oxygen defect concentration of the catalyst, which are the main reason of the improved toluene catalytic activity. Besides, this method was also applied to enhance toluene oxidation of iron mesh based monolithic catalyst. The 0.1MnCF-LDO/Iron mesh (IM) catalyst showed a 90% toluene conversion at around 316°C which was much lower than that of without MnO2 addition (359°C). In addition, the water resistant of all the catalysts was studied as well, all the samples showed relatively good water resistance. The toluene conversion still remained to be over >80% even in the presence of 10 vol.% water vapor.