Cu-Mn-CeOx loaded ceramic catalyst for non-thermal sterilization and microwave thermal catalysis of VOCs degradation

Abstract

Columnar aluminium oxide (Al2O3) commercial ceramic substrates were loaded with Cu-Mn-CeOx by impregnation and calcination. The morphologies, elements distribution and chemical structure were characterized. The room temperature sterilization activity of the catalysts against Hanseniaspora uvarum in air, liquid and 250 W microwave field was evaluated. Microwave catalytic combustion of volatile organic compounds (VOCs) under different operating conditions (concentration, flow rate and humidity) in continuous flow mode and their intermediate products in this process were studied. Results showed that the sterilization ratio of the Cu-Mn-CeOx modified substrates could reach 99.99% in different environments. The removal ratio of toluene, ethyl acetate and acetone with the concentration around 1600 mg m−3 under the microwave power of 250 W was all close to 100%. Synergistic effect of Cu-Mn-CeOx increased the atomic ratio of Oads/Olatt. The electron paramagnetic resonance (EPR) technique was used to explain the mechanism from the point of view of the defect structure of the materials and the generation of activated species. The defect structure of the materials and the generation of activated species during the reaction process were the main factors to obtain high efficiency on non-thermal sterilization and microwave thermal catalysis. This study indicated that the Cu-Mn-CeOx loaded ceramic catalyst had a wide application prospect in the field of air purification.