Preparation, Characterization and Activity of CuMnCeOx/CHC Catalyst in Microwave Catalytic Combustion of Toluene

The modification of cordierite honeycomb (CH) carrier is conducive to improve the catalytic activity of catalyst that applying in the treatment of real VOCs waste gas. A honeycombed calcium aluminum silicate hydrate (C–A–S–H) thin layer was self-assembled successfully by alkaline corrosion with supersaturated Ca(OH) 2 and contacted robustly onto the CH surface (named as CHC) by chemical bond. CuMnCeO x /CHC catalyst was prepared and applied in microwave catalytic combustion of toluene to check the catalytic activity in this work. Compared with CuMnCeO x /CH catalyst, CuMnCeO x /CHC catalyst exhibited a higher catalytic capacity and the removal rate of toluene reached 99%, which was higher than 75% of CuMnCeO x /CH catalyst under same reaction conditions of toluene initial concentration 1000 mg m −3 , air flow 0.12 m 3  h −1 and bed temperature 200 °C. Based on SEM, BET, XRD, XPS, UV-Raman, H 2 -TPR and NH 3 -TPD characterizations, it showed clearly that honeycombed C–A–S–H thin layer made CuMnCeO x active particles with smaller size more uniformly embedded into the pores of itself to hinder effectively the agglomeration of active particles in reaction. The valence reversible conversion of Cu + /Cu 2+ , Mn 2+ /Mn 3+ /Mn 4+ and Ce 3+ /Ce 4+ and total valence increase of CuMnCeO x produced abundant oxygen vacancies on the catalyst surface and simultaneously improved the transformation of surface adsorbed oxygen (O ads ) to lattice oxygen (O latt ). Toluene was oxidized completely by O ads and O latt species onto the active sites and “hot spots” under microwave irradiation that following both L–H mechanism and MvK mechanism. The research work lays down a theoretical basis for the preparation of highly effective catalyst and further application in the treatment of industrial VOCs waste gas. Graphical Abstract