Fabrication of Pt/Co3O4 nanocatalysts based on pollen template for low-temperature CO oxidation

Herein, we prepared supported Pt/Co3O4 nanocatalysts for CO oxidation by using a biological template method. It was found that the pollen template after base etching favored the deposition of Co(OH)2 and the fabrication of Co3O4 after calcination treatment. The Pt/bio-Co3O4-BB supported catalyst prepared by twice base etching treatments exhibited excellent catalytic activity, which could totally convert CO to CO2 at 70 degrees C. Especially, the first base etching treatment on the pollen template would etch a higher amount of biological components from the core of pollen, which was beneficial to the deposition of Co3O4, while the second base etching treatment on bio-Co3O4 support before the immobilization of Pt further modified the surface properties and improved catalyst activity. In-situ DRIFTS and XPS characterizations demonstrated that base treatment could promote the formation of oxygen vacancies and increase the surface ratio of Pt0/Pttotal, which enhanced the CO adsorption. Accordingly, we provide a new biological template synthetic strategy for catalysts with controlled morphology and good catalytic activity.