The Effect of Metal-Support Interactions on Formaldehyde Oxidation and By-Product Selectivities in TiO2 Supported Metal Catalysts (Co, Cr, Mo, and Ag).

One of the most significant indoor air pollutants is formaldehyde, and long-term exposure to HCHO may cause health problems. Catalytic oxidation at room temperature is an effective technology for removing HCHO indoors. In this paper, a simple sol-gel synthesis method was proposed for the preparation of TiO2 support, and a series of 5%M (Co, Cr, Mo, and Ag) catalysts were prepared by impregnation process. The materials were characterized by XRD, TEM, FT-IR, BET, and H-2 -TPR. The catalytic activities and the oxidation reaction of HCHO were investigated by an analytical system equipped with an infrared analyser (MKS multigas 2030) to analysis the different products. The results showed that the M/TiO2 catalysts obtained have TiO2 anatase phase diffraction peaks as well as a high surface area and porosity. The samples physicochemical, catalytic properties, and by-product selectivity's differ depending on the metal impregnated. The Ag/TiO2 catalyst was effective for the removal of formaldehyde gas at 95 degrees C, resulting in the selective production of carbon dioxide and water. The Co/TiO2 demonstrated complete conversion of HCHO at 244 degrees C and improved CO2 selectivity. The TEM images for the Ag/TiO2 catalyst showed that the silver particles were identified and very well dispersed on the support. Finally, these results might help in the development of high-performance catalysts activities at ambient temperature.