Abstract: Formaldehyde (HCHO) is an important indoor pollutant. Catalytic oxidize low concentration HCHO is an effective way to eliminate indoor pollution. In this study, a series of Pt/TiO₂ catalysts are prepared by impregnation and reduced by NaBH₄. The effects of loading amount of Pt and crystal type of TiO₂ on the physical and chemical properties and the catalytic performance in HCHO oxidation reaction are investigated. The results show that the quantity of active site and the oxygen vacancy of catalysts increased with increasing Pt content, which is beneficial to promote the further performance of catalysts. Nevertheless, with the further rises of Pt content, the specific surface area further decreases, and the proportion of Pt²⁺ species on the catalyst surface which is significant to catalytic properties also decreases, causing catalytic performance decreases. Compared with the catalyst supporting on rutile, the Pt/a-TiO₂ catalyst supporting on anatase has larger specific surface area, more Pt²⁺ phase and easier to form oxygen vacancy in the support, which cause better catalytic performance. The catalyst with Pt content of 0.1 wt% and supported by anatase TiO₂ has the best catalytic performance. The HCHO conversion efficiency reaches 98% and 100% at 50 ℃ and 100 ℃, and the stabilization time is longer than 140 h.

Key words: Catalyst support, Catalysis, Fixed-bed, Pt/TiO₂

摘要： Formaldehyde (HCHO) is an important indoor pollutant. Catalytic oxidize low concentration HCHO is an effective way to eliminate indoor pollution. In this study, a series of Pt/TiO₂ catalysts are prepared by impregnation and reduced by NaBH₄. The effects of loading amount of Pt and crystal type of TiO₂ on the physical and chemical properties and the catalytic performance in HCHO oxidation reaction are investigated. The results show that the quantity of active site and the oxygen vacancy of catalysts increased with increasing Pt content, which is beneficial to promote the further performance of catalysts. Nevertheless, with the further rises of Pt content, the specific surface area further decreases, and the proportion of Pt²⁺ species on the catalyst surface which is significant to catalytic properties also decreases, causing catalytic performance decreases. Compared with the catalyst supporting on rutile, the Pt/a-TiO₂ catalyst supporting on anatase has larger specific surface area, more Pt²⁺ phase and easier to form oxygen vacancy in the support, which cause better catalytic performance. The catalyst with Pt content of 0.1 wt% and supported by anatase TiO₂ has the best catalytic performance. The HCHO conversion efficiency reaches 98% and 100% at 50 ℃ and 100 ℃, and the stabilization time is longer than 140 h.

关键词: Catalyst support, Catalysis, Fixed-bed, Pt/TiO₂