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

Abstract

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 (Ov) 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.