Formaldehyde Oxidation on Pd/TiO2 Catalysts at Room Temperature: The Effects of Surface Oxygen Vacancies

Abstract

High reduction temperature generally induces the agglomeration of supported noble metals. Howerve, we found that high temperature reduction did not induce Pd particles sintering but improved Pd dispersion. Multiple methods were further carried out to illuminate the abnormal phenomenon. The results indicated more surface oxygen defects and diffusion of Pd particles were simultaneously induced by high temperature reduction. During diffusion process of Pd particles, they were trapped by the oxygen defects because of the strong metal-support interaction, which led to improvement of Pd dispersion on the Pd/TiO 2 -450R catalyst. In addition, more surface oxygen vacancies on the Pd/TiO 2 -450R catalyst resulted in more active sites of H 2 O activation to form abundant surface OH groups which further enhanced adsorbed O 2 activation and mobility, and then opening a more effective pathway for HCHO oxidation, which result in its high activity of Pd/TiO 2 -450R for ambient HCHO oxidation.

Oxygen Vacancy-Mediated Z-Scheme Charge Transfer in a 2D/1D B-Doped g-C3N4/rGO/TiO2 Heterojunction Visible Light-Driven Photocatalyst for Simultaneous/Efficient Oxygen Reduction Reaction and Alcohol Oxidation

“…After loading of BCN and rGO, the lowest frequency of the E g mode shifted to 152.2 cm –1 for TBCN@3%rGO (Figure S6, inset). The widening and blue shift of the E g mode is due to the formation of an oxygen vacancy on the surface of the photocatalyst …”

Reactive oxygen species on transition metal-based catalysts for sustainable environmental applications

“…Catalytic oxidation is the most appealing pathway to process effluent streams with dilute VOC (<0.5 vol%). 290,291 Conventional catalysts required for the oxidation of HCHO 292 normally contain noble metals (e.g., Pt, Au, Pd, and Ag) that are costly and poorly available, and cheap and thermally stable TMO catalysts are excellent alternatives although their efficiency may be NW@Ni foam) as a stable catalyst for the highly efficient oxidation of HCHO to formate (Fig. 21a), and used the OVs-free Co 3 O 4 NW@Ni foam and Co 3 O 4 nanoparticles (Co 3 O 4 NPs) to compare and characterize the catalytic performance.…”

“…Catalytic oxidation is the most appealing pathway to process effluent streams with dilute VOC (<0.5 vol%). 290,291 Conventional catalysts required for the oxidation of HCHO 292 normally contain noble metals ( e.g. , Pt, Au, Pd, and Ag) that are costly and poorly available, and cheap and thermally stable TMO catalysts are excellent alternatives although their efficiency may be somewhat lower.…”

A simple method to regulate surface hydroxy groups on Al2O3 for improving catalytic oxidation performance for HCHO on Pt/Al2O3

“…S10, † it was almost impossible for Pt/Al-2h to oxidize HCHO, while Pt-Na/Al-2h could oxidize around 10% reached approximately 25% HCHO conversion, which proved the significance of H 2 O in HCHO oxidation. 14,34,45,46 To explore the behavior of HCHO adsorption and conversion, in situ DRIFT spectra were obtained upon exposure to a stream containing HCHO gas at 30 °C. As shown in Fig.…”