Defective domain control of TiO2 support in Pt/TiO2 for room temperature formaldehyde (HCHO) remediation

Abstract

Sustainable and effective formaldehyde (HCHO) remediation at room temperature has significant potential in next-generation indoor environment purification technology. Herein, defective anatase TiO2 was synthesized using chemical vapor condensation (CVC) and was subsequently impregnated with 0.08 wt% Pt. The resulting Pt/CVC-TiO2 catalyst was used for the room-temperature conversion of HCHO and exhibited a HCHO removal efficiency of 80% under continuous flow conditions (GHSV 100,000 cm(3) h(-1) g(cat)(-1)) with an initial concentration of 10 ppm with good stability over 600 min. The characterization results confirmed the metallic oxidation state (Pt-0), oxygen vacancies (mainly F centers), disordered domains, and strong interaction between Pt and defective TiO2 were essential for high activity. Moreover, electron paramagnetic resonance (EPR) analysis showed the consistent stability of the defective domains of CVC-TiO2, imparting catalytic stability over multiple cycles. This study highlights the synergistic relationship between oxygen vacancies in the TiO2 support and the resulting HCHO oxidation functionality.