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.