Selective catalytic reduction of NOx with H2 over WO3 promoted Pt/TiO2 catalyst

Abstract Pt/TiO 2 and WO 3 modified Pt/TiO 2 catalysts have been investigated for the selective catalytic reduction of NO x by H 2 (H 2 -SCR) in the presence of oxygen. It was found that the addition of WO 3 leads to a significant promoting effect on the low-temperature activity of Pt/TiO 2 catalyst and the optimal loading is 2%. X-ray absorption near-edge structure (XANES) revealed the electron transfer from WO 3 to Pt active sites, leading to the formation of metallic Pt, which is responsible for the low-temperature H 2 -SCR of NO x . In-situ DRIFTS demonstrated that the introduction of WO 3 to Pt catalyst not only contributes to the formation of reactive adsorbed NO x species on the catalyst, but also promotes the formation of NH 4 + species. All of these factors, collectively, account for the improved low-temperature activity of Pt-WO 3 /TiO 2 catalyst.