Low-temperature catalytic performance improvement of Ru/TiO2{001} for o-dichlorobenzene oxidation

Abstract

Chlorinated aromatics hydrocarbons were harmful to ecology and human health, whose catalytic combustion encounters problem of catalyst deactivation by chlorine poisoning. To simultaneously improve the catalytic activity, CO2 selectivity and stability of catalyst, the present study used the loading of Ru active component on the anatase TiO2 which preferentially exposes highly active {001} crystalline facets. Take o-dichlorobenzene (o-DCB) oxidation as a surrogate reaction, Ru/TiO2{001} showed lower T90% (temperatures with 90% conversion), higher CO2 selectivity and better stability than Pt/TiO2{001}, Pd/TiO2{001} and Ru/commercial TiO2 (Ru/TiO2-C). The excellent results could be attributed to the strong metal support interaction between Ru species and TiO2{001}, with more oxygen vacancies and higher surface oxygen concentration, more Lewis acid sites, enhanced low-temperature reducibility, more surface Ti3+ species, more surface Ru4+ species, and highly dispersed Ru species, favoring the excellent low temperature catalytic activity and CO2 selectivity of Ru/TiO2{001}. In addition, the less Cl species on the used 1.5% Ru/TiO2{001} indicated their effectively removal, which is the core issue for the deep oxidation of o-DCB. Furthermore, the in situ FTIR spectroscopy gave the detail oxidation route of o-DCB over 1.5% Ru/TiO2{001}, that the co-adsorption of o-DCB and O2 on Ru/TiO2{001} surface were calculated based on the density functional theory calculations. The present study gave a new insight into the new pathway for the design of promising catalysts for the treatment of CAHs.