Pt single atoms and defect engineering of TiO-nanosheet-assembled hierarchical spheres for efficient room-temperature HCHO oxidation.

Achieving high atomic utilization and low cost of desirable Pt/TiO catalysts is a major challenge for room temperature HCHO oxidation. Here, the strategy of anchoring stable Pt single atoms by abundant oxygen vacancies over TiO-nanosheet-assembled hierarchical spheres (Pt/TiO-HS) was designed to eliminate HCHO. A superior HCHO oxidation activity and CO yield (∼100% CO yield) at relative humidity (RH) > 50% over Pt/TiO-HS is achieved for long-term run. We attribute the excellent HCHO oxidation performance to the stable isolated Pt single atoms anchored on the defective TiO-HS surface. The Pt on the Pt/TiO-HS surface has a facile intense electron transfer with the support by forming Pt-O-Ti linkages, driving HCHO oxidation effectively. Further in situ HCHO-DRIFTS revealed that the dioxymethylene (DOM) and HCOOH/HCOO intermediates were further degraded via active OH and adsorbed oxygen on the Pt/TiO-HS surface, respectively. This work may pave the way for the next generation of advanced catalytic materials for high-efficiency catalytic HCHO oxidation at room temperature.