Influence of Modifications to the Pechini Method on the Electroactivity and Stability of Pt-RuO_x/C Catalysts

Abstract

Since electrode electroactivity and stability depend directly on the nature, morphology, and structure of the material, we have investigated how modifications to the Pechini method during the synthesis of Pt-RuO x /C electrocatalysts affected catalyst activity. The structure and stability of the resulting materials were investigated after their submission to a large number of potential scans and to constant potential for a prolonged time period in sulfuric acid 0.5 mol L −1 and methanol 0.1 mol L −1 solution. DMFC tests were accomplished using membrane electrode assemblies (MEAs) prepared by hot-pressing a pretreated Nafion 117 membrane together with the prepared Pt-RuO x anodes and a Pt cathode (from E-TEK), in order to compare the catalytic activity of the materials prepared by different methods. The stability studies demonstrated that the catalyst whose resin/carbon support mixture was agitated in a balls mill before undergoing heat-treatment was more stable than the other prepared catalysts. The catalysts synthesized with the single resin consisting of Pt and Ru and subjected to ultrasound before heat-treatment furnished the highest power density in the single fuel cell.

Graphitized Nanodiamond as Highly Efficient Support of Electrocatalysts for Oxygen Reduction Reaction

“…They are usually used as a secondary support, which works together with the primary electrocatalyst support (carbon materials), to improve electrocatalyst performance. 12,13 Recently, nanodiamond (ND) synthesized by detonation or milling of synthetic microdiamonds was received attention as a stable supporting material due to its superior thermal and chemical stability. [14][15][16][17][18][19][20] In order to improve ND's conductivity, we took a vacuum annealing on ND powder and produced a graphitic shell on the ND surface.…”