Construction of spinel/biochar film/honeycomb monolithic catalyst for photothermal catalytic oxidation of VOCs

Photothermal catalytic oxidation emerges as a promising method for the removal of volatile organic compounds (VOCs). Herein, via sol-gel impregnation method, spinel CuMn2O4 was coated on attapulgite honeycombs with integrating biochar (BC) film as the second carrier, using chestnut shell as complexation agent. Various mass ratios of CuMn2O4 to chestnut shell was modulated to investigate the catalytic toluene degradation performance. Results indicated that the monolithic CuMn2O4/BC/honeycomb catalyst demonstrated superior photothermal catalytic toluene degradation with a low T90 (temperature at 90% degradation) of 263 °C when the mass ratio of CuMn2O4 to biomass was 1:4. The addition of BC film substantially increased the honeycomb’s specific surface area and improved the photothermal conversion of spinel, leading to enhanced photothermal catalytic activity. This study presents a cost-effective strategy for eliminating industrial VOCs using clay-biomass based monolithic catalyst.