Catalytic oxidation of dichloromethane over W-Nb composite oxide catalysts modified by Co: The influence of redox ability and acidity

Catalytic oxidation of highly toxic chlorinated volatile organic compounds often places high demands on the anti-poisoning ability of the catalysts. Here, Co/WNb catalysts with different Co loadings were prepared for the catalytic oxidation of dichloromethane (DCM). Notably, the interaction between the active components and the carriers resulted in a high Co²⁺/Co³⁺ ratio on the catalyst surface, which facilitated the generation of oxygen vacancies (O_v) and enhanced the redox properties of the catalyst. Furthermore, the WNb carrier offered ample surface acidic sites, bolstering the catalyst's resilience against chlorine poisoning. The study revealed that achieving a more balanced combination of redox properties and acidity was beneficial for enhancing the catalytic degradation efficiency of DCM. 3% Co/WNb exhibited the best catalytic activity (T₉₀ = 269 °C). The catalyst also exhibited excellent stability and outstanding water resistance. Potential reaction routes for the catalytic oxidation of DCM were explored using in-situ IR spectra analysis. This study offers novel insights for the development of efficient, stable, and environmentally friendly catalysts for DCM degradation.