Gas-phase total oxidation of nitric oxide using hydrogen peroxide vapor over Pt/TiO2

Abstract Pt/TiO 2 catalysts with various Pt loadings (0.1–0.7 wt.%) were synthesized by a combined wet impregnation and H 2 -reduction method. The as-prepared catalysts were firstly reported being applied in thermal catalytic decomposition of hydrogen peroxide (H 2 O 2 ) vapor for treating NO X . Physico-chemical properties of Pt/TiO 2 catalysts were investigated by comprehensive techniques, including XRD, Raman, N 2 adsorption–desorption, TEM, UV–vis DRS, XPS and PL spectroscopy. The activity tests showed that the incorporation of platinum into TiO 2 led to a significant increase in the catalytic oxidation of NO compared with the unmodified TiO 2 . Toward NO oxidation from H 2 O 2 vapor (molar ratio = 12/1), 0.3 wt.% Pt-TiO 2 exhibited a remarkable activity in NO X removal (96.7%) and a high selectivity (89.2%) in their conversion to nitrate species under the optimal condition. XRD and TEM results show that ultrafine Pt particles were well dispersed on the surface of anatase-phase TiO 2 . XPS analysis indicated that Pt dopant existed as mainly metallic Pt (0) and a small portion of Pt 2+ in as-prepared materials. The results of PL spectra demonstrated that the platinum nanoparticles on the TiO 2 surface significantly accelerated electron transfer and served as active sites for the adsorption and activation of H 2 O 2 molecules, to facilitate the generation of hydroxyl groups.