Hydroxyl Enhanced Structured Pt/Nix/a-AlOOH Catalyst for Formaldehyde Oxidation at Room Temperature

Abstract
Ni promoted structured plate-type Pt/Nix/a-AlOOH catalysts were developed to enhance the amount of hydroxyl group, therefore improving the catalytic activities for formaldehyde oxidation at room temperature. The analyzation results by XRD and HRTEM indicate that two kinds of materials, AlOOH and NiOOH, are detected on the surface of Pt/Nix/a-AlOOH. It can be seen from the result of TG that the hydroxyl group on the catalyst surface increased after Ni was loaded. Furtherly, XPS results show that the percentage of hydroxyl groups which can effectively absorb formaldehyde increases from 36.4% to 72.8% by doping Ni. In addition, the content of Pt0 increased from 27.5% to 45%. The results indicate that optimized Pt1.15/Ni3.1/a-AlOOH has the best catalytic activity with the CO2 conversion is 88% at 25°C and 100% at 40°C, while CO2 conversion over Pt1.2/a-AlOOH is 56% at 25°C and 100% at 100°C respectively. Hence, the Ni promoted plate-type Pt/a-AlOOH possesses high efficiency and it provides a new idea for catalyst design of formaldehyde oxidation.