ELECTROCHEMICALLY DEALLYOED PD-CU CATALYSTS FOR OXYGEN REDUCTION REACTION

摘要：

Polymer electrolyte membrane fuel cells (PEMFC) are a promising technology for stationary and portable power applications and have the potential to reduce fossil fuel and greenhouse gas emissions by converting hydrogen and oxygen directly into electricity and water. However, slow kinetics of the oxygen reduction reaction (ORR) on Pt-based catalysts at the cathode limits the efficiency of these fuel cells. This low-efficiency cathode and the requisite high Pt loading (high cost) hinders the widespread application of PEMFCs. This has resulted in research focused on increasing the activity of ORR catalysts and lowering the overall Pt loading or replace Pt with other non-Pt catalysts. In this study, the dealloyed Pd-Cu thin film catalysts (i.e. non-Pt catalysts) were prepared by electrochemical dealloying of Cu-rich Cu3Pd bimetallic precursors. Their catalytic activities for oxygen reduction reaction (ORR) have been investigated in 0.1 mol ·L‐1 HCIO4 . The dealloyed Pd-Cu thin films shows a ~2.0 fold increase in the specific oxygen reduction activity over pure Pd thin films as measured by a rotating disk electrode (RDE). The structures of the dealloyed Pd-Cu catalysts were revealed by synchrotron-based anomalous X-ray diffraction (AXRD) at an atomic scale. The catalytic activity enhancement of the dealloyed Pd-Cu is mainly attributed to the strain change in the Pd overlayer formed on the surface after dealloying. We compare our results on dealloyed Pd-Cu thin films to our previous results on Pt-Cu thin films prepared from dealloying of Cu3Pt precursors. Our results show that the strain is related to the thickness of Pd overlayer, which is affected by the the diffusion coefficient of the constituent element.These studies provide a better understanding of the structure and composition relationships in the materials prepared by dealloying base metal rich alloys.

关键词： Polymer electrolyte membranes(PEMFCs) Oxygen reduction reaction (ORR) Electrochemically dealloying Pd-Cu alloy Electrocatalyst

作者: Ruizhi Yang Peter Strasser Michael F.Toney

作者单位: School of Energy, Soochow University, Suzhou, 215006, China Stanford Institute for Materials and En Department of Chemistry, Chemical Engineering Division,Technical University Berlin, Berlin 10623, Ge Stanford Institute for Materials and Energy Science, California 94025, USA Stanford Synchrotron Radi

会议类型: 国际会议

会议名称: The 7th International Green Energy Conference & The 1st DNL Conference on Clean Energy(第七届绿色能源国际会议暨第一届DNL洁净能源会议(IGEC)

会议地点: 大连

会议语种:英文

页码: 50

在线出版日期: 2012-05-28（万方平台首次上网日期，不代表论文的发表时间）