Catalytic combustion of dichloromethane over supported CoCr2O4/TUD-1 catalysts: The effect of CoCr2O4 particle size on the modification of surface properties and the catalytic performance

A series of supported CoCr 2 O 4 /TUD-1 catalysts with different loadings were prepared and tested for catalytic combustion of dichloromethane, in order to investigate the effect of particle size on the catalyst properties and related catalytic behaviors. It was found that the supported catalyst with low content of CoCr 2 O 4 had smaller CoCr 2 O 4 particles compared to that with high content, as revealed by the XRD results. Consequently, the changes in particle size altered the surface composition of the catalyst, as the small particles contained higher content of surface Cr 6+ species compared to the large ones. The enrichment of Cr 6+ species improved catalyst reducibility and surface acidity, which synergistically governed the observed catalytic behaviors. As a reuslt, the 5CoCr 2 O 4 /TUD-1 catalyst had the highest reaction rate of 64.8   ×   10 −7   molDCM   g −1 CoCr2o4s −1 , due to its best reducibility and highest surface acidity.