Active surface RuOx species originating from size-driving self-dispersion process for toluene catalytic combustion

Abstract

Catalytic combustion method is an effective way to degrade aromatic volatile organic compounds (VOCs). The size of Ru species significantly affect the catalytic performance, while lack of enough concern for VOCs catalytic oxidation. In this work, we deposited a series of Ru nanoparticles (1.6, 2.9, and 3.6 nm) on CeO2 support for toluene catalytic combustion, and reported a size-dependent performance under oxidizing atmosphere. The catalytic performance was improved with the decrease of Ru size (T90 = 214 °C on 1.6RuCe-SD, compared to 228 °C of 3.6RuCe-SD, and 244 °C of RuCe-IM). The drastic activity improvement may result from the smallest size of Ru and the highest formation degree of coordinatively-unsaturated sites during a self-dispersion (redispersion) process. The active surface RuOx species originating from the smaller Ru contain a higher ratio of active Run+, oxygen vacancy, and stronger ability to facilitate dehydrogenation and aromatic ring breakage, thus eventually boosting the toluene combustion activity. This work brings forward a simple strategy to expose coordinatively-unsaturated sites based on size-driving self-dispersion for catalyst design for the elimination of typical VOCs and other environmental applications.