Blocking the non-selective sites through surface plasmon-induced deposition of metal oxide on Au/TiO2 for CO-PROX reaction

Summary CO preferential oxidation (PROX) in excess hydrogen is a promising strategy for CO removal in hydrogen-rich reformate. However, the CO conversion and CO2 selectivity in the PROX reaction dramatically decrease with rising temperature, resulting in a major challenge to complete CO removal across a wide temperature window. Here, we developed a photoexcited deposition of metal oxide (PDMO) method based on surface plasmonic resonance of Au nanoparticles, which can tune the interfacial properties by depositing lead oxide at the Au-TiO2 interface. The interface modified Pb3O4/Au/TiO2 catalyst can successfully eliminate CO in a wide temperature range (70°C–140°C) and exhibit superior stability in the PROX reaction. Further experiments demonstrated that the improved PROX performance is due to the severely depressed hydrogen oxidation through simultaneously inhibiting the activation of hydrogen and oxygen. The results further reveal that the interface of Au/TiO2 is the superactive but non-selective site for H2 and CO oxidation.