Thermocatalytic oxidation of gaseous benzene by a titanium dioxide supported platinum catalyst

Abstract

Highly active platinum (Pt)-based nanostructured materials are expected as catalysts to effectively mineralize recalcitrant aromatic volatile organic compounds (e.g., benzene) even at low temperature conditions. In this regard, the utility of a titanium dioxide (TiO2) supported Pt (1 wt%) catalyst was explored for the thermocatalytic oxidation of benzene in the air. The superior performance of Pt/TiO2-R (‘R’ denotes the high-temperature hydrogen-based reduction pre-treatment of the catalyst) over its non-reduced counterpart was attributed to the increase in metallic Pt (Pt0) nanoparticles present on the TiO2 surface alongside strong metal-support interactions (SMSIs). The SMSIs at the Pt-TiO2 interface partially reduced the metal oxide structure to generate Ti3+ centers, giving rise to oxygen vacancies. The analysis of in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) revealed that the benzene molecules are oxidized into carbon dioxide via phenolate, benzoquinone, carboxylate, and carbon monoxide intermediates. The present study offers new insights into the application of Pt-based high-performance catalysts for achieving complete removal of benzene at low temperatures.