Prepatation And Electrochemical Performance Of Pt-SnO₂/C Nano Composite Catalyst

SnO2nanoparticles as an auxiliary catalyst have been concerned widely in direct methanol fuel cell. This paper chose a new method--ultrasonic auxiliary method synthesizes SnO2/C catalyst. SnO2nanoparticles are homogeneously dispersed on carbon blacks with the size below10nm. This method has many advantages:it has a simple procedure without redundant oxidant surfactant. Through the analysis of the experimental parameters and conditions, we speculate the mechanism of formation of nano SnO2catalysts with excellent loading morphology.The Pt-SnO2/C nanocomposite catalyst was prepared successfully using ethylene glycol reduction method in SnO2/C base. The related electrochemical catalytic performance characterization was tested, including active specific surface area test, oxygen reduction catalytic reaction and methanol oxidation catalytic reaction and CO removal experiments in acid system. Results show that the Pt-SnO2/C nanocomposite catalyst has higher active surface area than Pt/C catalyst. Through the kinetics process analysis of oxygen reduction reaction, the reaction was conducted in4electronic reaction steps and it has higher catalytic activity than Pt/C catalyst. In the methanol oxidation performance test and CO removal experiments, Pt-SnO2/C nanocomposite catalyst showed the highest peak current density, more stable catalytic properties and the more negative potential for CO oxidation. In general, Pt-SnO2/C catalyst has better electric catalytic performance. This paper also used carbon microbeads and graphitized carbon microbeads as carrier to prepare Pt-SnO2nano composite catalyst. Pt-SnO2*carbon microbeads catalysts in different carbon microbeads were prepared through ultrasonic auxiliary method and ethylene glycol reduction method. For the graphitized carbon microbeads, the different acidizing conditions and the solvent system with loading SnO2were considered to facilitate the loading of nano SnO2particles. Electrochemical experiments show higher peak current and lower onset potential of methanol electrooxidation on Pt-SnO2/carbon microbeads than on Pt/carbon microbeads.This work shows that Pt-SnO2/C is a promising catalyst for direct methanol fuel cells in terms of its high activity towards methanol electrooxidation and oxygen reduction reaction. It revels that SnO2nanoparticles truly have enhanced role to Pt/C catalyst.