Selective Adsorption of Chlorine Species on RuO2 Sites for Efficient Elimination of Vinyl Chloride on the Ru/SnO2 Catalyst.

The main bottleneck in the catalytic combustion of chlorinated volatile organic compounds (CVOCs) is deactivation and the production of chlorine-containing byproducts originating from the chlorine species deposited on the catalyst. Herein, Ru supported on SnO2 (Ru/SnO2) was prepared with the lattice matching principle. As RuO2 and SnO2 are both rutile phases, Ru species were present as highly dispersed RuO2 particles on the Ru/SnO2 catalyst. These particles adsorbed chlorine species with greater efficiency during the CVOCs combustion, thereby protecting the oxygen vacancies. Therefore, the double sites, oxygen vacancy to oxidize and RuO2 to adsorb chlorine species, on the Ru/SnO2 catalyst led to a notable enhancement in activity, stability, and byproduct selectivity. In contrast, the high dispersion of Ru species on the CeO2 support, as the typical catalyst for chlorinated hydrocarbon combustion, gave rise to a predominantly Ru-O-Ce structure. This structure did not prevent the adsorption of chlorine species on the oxygen vacancies, resulting in deactivation at low temperatures and an increased polychlorinated byproduct concentration. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) further corroborated the variation in the adsorption sites of chlorine species on the two catalysts. This work provides a new strategy for designing efficient Ru-based catalysts for catalytic CVOCs combustion.