A Novel Porous Ceramic Membrane Supported Monolithic Cu-Doped Mn–Ce Catalysts for Benzene Combustion

Zhaxi Cuo,Yan Gong,Feng Zhao,Haidi Liu,Dongdong Wang,Yunfa Chen

doi:10.3390/catal9080652

Abstract

Porous ceramic membranes (PCMs) are considered as an efficient hot gas filtration material in industrial systems. Functionalization of the PCMs with high-efficiency catalysts for the abatement of volatile organic compounds (VOCs) during dust elimination is a promising way to purify the industrial exhaust gases. In this work, we prepared PCMs (porosity: 70%) in a facile sintering process and integrated Cu-doped Mn–Ce oxides into the PCMs as monolithic catalysts by the sol–gel method for benzene oxidation. Through this method, the catalysts are dispersed evenly throughout the PCMs with excellent adhesion, and the catalytic PCMs provided more active sites for the reactant gases during the catalytic reaction process compared to the powder catalysts. The physicochemical properties of PCMs and catalytic PCMs were characterized systematically, and the catalytic activities were measured in total oxidation of benzene. As a result, all the prepared catalytic PCMs exhibited high catalytic activity for benzene oxidation. Significantly, the monolithic catalyst of Cu0.2Mn0.6Ce0.2/PCMs obtained the lowest temperature for benzene conversion efficiency of 90% (T90) at 212 °C with a high gaseous hourly space velocity of 5000 h−1 and showed strong resistance to high humidity (90 vol.%, 20 °C) with long-term stability in continuous benzene stream, which is caused by abundant active adsorbed oxygen, more surficial oxygen vacancy, and lower-temperature reducibility.

Highlights

In recent years, air pollution, the fine particulate matters (PM2.5 ), has aroused general concern in China [1,2,3,4]
Throughout the measuring process, the CO2 selectivity was always more than 98.0%, and there were no other products of incomplete oxidation detected, suggesting that the degree of catalytic oxidation is almost complete in the reaction
We successfully fabricated porous ceramic membranes which served as a catalyst support

Summary

Introduction

Air pollution, the fine particulate matters (PM2.5 ), has aroused general concern in China [1,2,3,4]. Diverse industrial processes and the ignition of non-renewable energy sources produce different kinds of volatile organic compounds (VOCs) containing PM2.5 which cause serious toxicological and unexpected side effects on the urban air quality, human body, and even on the climatic condition as secondary pollutants [5,6]. The effective filter materials of porous ceramic membranes (PCMs) were broadly utilized for PMs filtration owing to its unique properties, such as low density, high open porosity, high strength and toughness, incredible high temperature, and chemical resistance in the hot gas filtration processes [7,8,9,10]. For eliminating VOCs emissions, the catalytic oxidation is regarded as a compelling strategy compared to other VOCs disposal techniques, attributable to its Catalysts 2019, 9, 652; doi:10.3390/catal9080652 www.mdpi.com/journal/catalysts

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Results

Conclusion