Effect of Ni-V loading on the performance of hollow anatase TiO2 in the catalytic combustion of dichloromethane.

A catalyst based on mixed V-Ni oxides supported on TiO2 (Ni-V/TiO2) was obtained using the sol-gel method. Its catalytic performance relative to dichloromethane (DCM) degradation was investigated. Characterization and analysis were conducted using transmission electron microscopy, H2 temperature-programmed reduction, pyridine-Fourier transform infrared spectroscopy (FTIR) characterization, and X-ray diffraction. Results showed that the original hollow anatase structure of pure TiO2 was well-maintained after Ni-V loading. The loading of NiO-VOx not only significantly improved the stability of pure TiO2 but also inhibited the formation of the by-product monochloromethane (MCM). Among the series of Ni-V/TiO2 catalysts, 4%Ni-V/TiO2 possessed the highest catalytic activity, with 90% DCM conversion at only 203°C. No by-products and no significant changes in the catalytic activity were observed during combustion of DCM after 100 hr of a continuous stability test. Furthermore, thermogravimetric analysis (O2-TG) and energy dispersive spectrometer (EDS) characterization of the used 4%Ni-V/TiO2 catalyst revealed that no coke deposition or chlorine species could be detected on the catalyst surface.