Effect of coating modification of cordierite carrier on catalytic performance of supported NiMnO₃ catalysts for VOCs combustion

NiMnO₃ perovskite catalysts supported on cordierite modified by Ce_xZr_1-xO₂ coatings were prepared using impregnation and sol–gel methods for catalytic combustion of single/double component VOCs at different concentrations and GHSV of 15,000 h⁻¹, which were characterized by BET, XRD, SEM, FT-IR, H₂-TPR and O₂-TPD. After coating modification, the specific surface area of catalysts is improved obviously. Among the catalysts, the Ce_0.75Zr_0.25O₂ coating modified NiMnO₃ catalyst exhibits the best catalytic activity for VOCs combustion with 95.6% conversion at 275 °C and has stable activity when catalyst is embalmed at 800 °C. In addition, the catalyst also presents the excellent water-resistant and conversion stability over time-on-stream condition. The reason is that Ce_0.75Zr_0.25O₂ coating can promote more lattice distortion and defects and smaller crystal size, which improve oxygen transfer capability and dispersion of active component.