Pt-support interaction and nanoparticle size effect in Pt/CeO2-TiO2 catalysts for low temperature VOCs removal

A series of Pt/CeO2-TiO2 catalysts (0.5 wt% Pt) with size-controllable Pt nanoparticles were prepared by a modified ethylene glycol reduction method and the Pt particle size effect of Pt/CeO2-TiO2 catalysts on benzene and 1,2-dichloroethane (DCE) degradation was investigated. It reveals that the metal-support interaction of PtOx species and CeO2-TiO2 mixed oxides is enhanced by the reduced Pt particle sizes. The formation of more Pt2+ species and stronger redox properties at low-temperature resulted by the enhanced metal-support interaction of Pt/CeO2-TiO2 catalysts both greatly promotes the deep oxidation for benzene and C2H3Cl byproduct during DCE degradation at low temperature. Pt/CeTi-11 with the smallest average Pt particle size (1.53 nm) exhibits the highest activity among all the catalysts for benzene degradation, with T-90(%) of only 152 degrees C (1000 ppm, GHSV = 15,000 h(-1)). However, more acidic sites (especially the strong acid) were formed on the Pt/CeO2-TiO2 catalysts with bigger Pt nanoparticle (>2.95 nm), contributing to activate and convert DCE to C2H3Cl. More importantly, Pt/CeO2-TiO2 catalysts are extremely stable in DCE degradation reaction, and have been scarcely influenced by the presence of benzene and water in the feed gases. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

The size of Pt nanoparticles in Pt/CeO2-TiO2 catalysts affects their degradation activity towards benzene and 1,2-dichloroethane (DCE), with smaller Pt particle sizes enhancing the metal-support interaction and redox properties for deep oxidation at low temperature. Additionally, Pt/CeO2-TiO2 catalysts with larger Pt nanoparticles exhibit more acidic sites, contributing to the conversion of DCE to C2H3Cl. Furthermore, Pt/CeO2-TiO2 catalysts show high stability in DCE degradation reactions and are minimally affected by the presence of benzene and water in the feed gases.