BACKGROUNDChemical vapor deposition (CVD) is a promising catalyst preparation method owing to high dispersion and small particles of metallic oxides. Besides, the ZSM-5 zeolite membrane is used to treat volatile organic compounds (VOCs) due to relatively high contact efficiency, lower bed pressure drop and mass transfer resistance than granular ZSM-5, giving good stability of the metal catalysts. However, Cr modified ZSM-5 zeolite membrane prepared by CVD for trichloroethylene (TCE) catalytic oxidation was still not well-studied. In the present study, a series of Cr(x)/ZSM-5/PSSF (x=1, 3, 5 and 7) catalysts with different Cr loadings was prepared by CVD and further characterized by nitrogen gas (N-2) adsorption and desorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), ammonia temperature-programmed desorption (NH3-TPD) and X-ray photoelectron spectroscopy (XPS), as well as catalytic performance for TCE oxidation. RESULTSThe results showed that the Cr2O3 species were uniformly dispersed on the surface of ZSM-5/PSSF, and that the Cr(1)/ZP catalyst exhibited the best catalytic activity for TCE oxidation owing to more Cr6+ species and adsorbed oxygen. It also demonstrated that the Cr(1)/ZP catalyst shows superior catalytic performance for TCE oxidation, giving a T-90 that is about 62 degrees C (c.15%) lower than 1% Cr/ZSM-5 particle catalyst. Furthermore, it exhibited an excellent stability after online testing at 440 degrees C for 30h, and then dropped from 91% to 62% after 95h, finally remaining at 62% after 120h. CONCLUSIONThe study demonstrated that Cr/ZSM-5 zoelite membrane catalysts prepared by CVD show better catalytic behavior and stability for catalytic oxidation of TCE than Cr/ZSM-5 zoelite catalysts. (c) 2019 Society of Chemical Industry