Photodeposition of alloyed Au-Pt nanoparticles on TiO2 for the enhanced catalytic oxidation of HCHO at room temperature

Catalytic oxidation has been considered as one of the most promising strategies for the removal of indoor HCHO which causes multiple health problems. Alloyed Au-Pt showed potential for catalytic oxidation reactions, but the reports on HCHO oxidation are limited. In addition,understanding on the catalytic mechanism is lacking. In this work, a sodium citrate assistant photodeposition process was developed to fabricate highly dispersed dual Au-Pt alloy with 2–3 nm on the surface of TiO2. The turnover frequency of Au-Pt/TiO2 (68.6 h-1) is much higher than that of Pt/TiO2 (19.9 h-1). This enhancement was also confirmed on different TiO2 supports and with different Pt loading. Based on the experimental and density functional theory calculations, it was found that the alloyed Au-Pt has more metallic Pt and is beneficial for the adsorption and dissociation of oxygen. Therefore, the rapid conversion of dioxymethylene species to formate species, with reduced reaction barrier, promotes the performance in catalytic oxidation of HCHO.