High efficiency CuOx/TiO2-ZrO2 for chlorobenzenes catalytic oxidation via adjusting surface acidic sites

Abstract

A series of CuOx/TiO2-ZrO2 (Cu/TZ) catalysts were prepared and applied in catalytic elimination chlorobenzene. Cu/TZ exhibited a 90% CB conversion at a relatively lowest temperature (249 °C), following by a lower activation energy (27.1 kJ/mol) and a higher reaction rate (11.5 × 10-7 mmol s−1 gcat-1 at 260 °C) in comparison with Cu/T and Cu/Z. Systematically surface properties and structural analysis indicated that the superior performance over Cu/TZ could mainly result from its well-dispersed CuOx active species, the abundant surface adsorbed oxygen, and the plentiful surface acid density (102.5 μmol/gcat), especially the Lewis acid sites. Detailed in in situ DRIFTS results further demonstrated the smooth adsorption of CB on those Lewis acid sites over Cu/TZ, which in turn facilitated subsequent C-Cl bond breaking and the catalytic oxidation of the nucleophilic oxygen, thus contributing to its superior catalytic performance. This study could help to guide the development of efficient catalysts for enhancing CB oxidation activity.