https://doi.org/10.1039/D2NR04261D

Abstract

Oxygen vacancies and Ru species regulation by aid of metal–organic frameworks, were synergically adopted in a rational design to upgrade the Ru/TiO2 catalyst, which is highly active for catalytic oxidation of dichloromethane (DCM) with less undesired byproducts. Herein, Ru/M-TiO2 and Ru/N-TiO2 catalysts were synthesized by pyrolysis of MIL-125 and NH2-MIL-125 incorporated with Ru, with the existence of Ru nanoclusters and nanoparticles detected by XAFS, respectively, and were analyzed with catalytic performance comprehensively. Complete oxidation of DCM was obtained at ~290 oC over Ru/M-TiO2 and Ru/N-TiO2 catalysts, while Ru/N-TiO2 showed quite less monochloromethane (MCM) and higher CO2 yield, better dechlorination capacity in the oxidation. The differentiation might be due to the easier desorption of chlorine over Ru4+ as the main activated adsorption sites over Ru/N-TiO2, while which were hard to be implemented on oxygen vacancies that as the main dissociation sites for DCM over Ru/M-TiO2. Additionally, Ru/N-TiO2 exhibited superior stability and excellent resilience in the moisture. In situ DRIFTS experiment further indicated the different DCM catalytic degradation process, as well as the reaction mechanism over as-prepared catalysts.

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