High-surface area mesoporous Pt/TiO₂ hollow chains for efficient formaldehyde decomposition at ambient temperature.

Room-temperature catalytic decomposition of formaldehyde (HCHO) is considered as one of the most main methods for the removal of indoor HCHO due to its facile reaction conditions. Herein, high-surface area mesoporous Pt/TiO2 hollow chains were synthesized in high yield by using a simple microwave-hydrothermal route, followed by a combined NaOH-assisted NaBH4-reduction deposition of Pt nanoparticles on the as-obtained TiO2 surface. The catalytic activity for HCHO decomposition was evaluated at room temperature. The prepared Pt/TiO2 hollow chains with an optimal Pt loading of 0.5 wt.% exhibited high catalytic activity and recyclability. The apparent reaction rate constant of HCHO oxidation over this catalyst was approximately 1.42×10(-3) ppm(-1) min(-1), exceeding that of the commercial Degussa P25 TiO2 with equal Pt content (k=5.36×10(-4) ppm(-1) min(-1)) by a factor of approximately 2.65. The high catalytic activity of the Pt/TiO2 hollow chains could be mainly attributed to the hollow chain-like structure, high specific surface area, numerous mesopores, and high pore volume of TiO2 support. Consequently, the catalysts exhibited high adsorption capacity for HCHO, fast diffusion and transport of gas molecules, and good contact between gases and active sites. These characteristics enhanced the catalytic activity.