High catalytic performance and stability of Pt/C using acetic acid functionalized carbon

Abstract

Abstract Carbon (Vulcan XC-72, Cobat Corp.) is pretreated using acetic acid (HAC) before the Pt deposition by microwave assisted glycol method. TEM and XRD results indicate that 3 nm Pt nano-particles are uniformly dispersed on the surface of modified XC-72. In order to examine the interaction between Pt nano-particles and carbon, Pt/C-HAC and commercial Pt/C (Johnson Matthey Corp.) are calcined at 500 °C for 2 h under nitrogen atmosphere. The average Pt particle size of Pt/C-HAC after calcination is only 10–12 nm in diameter while commercial Pt particles grow up to 25–35 nm with a broad size distribution. Meanwhile, electrochemical studies of Pt/C-HAC reveal higher activity and stability for both methanol oxidation and oxygen reduction than that of Pt/C-JM. The pore structure and surface composition are investigated by BET and XPS, which implies that much microporous structure and carbonyl functional groups on carbon surface are obtained after HAC treatment. The high catalytic performance and stability might mainly be due to the strong interaction between Pt nano-particles and carbon by carbonyl functional groups. Therefore, HAC treatment is proved to be a facile and effective method for carbon as the support for Pt as fuel cell catalyst.