NSF-DFG Echem: Surface Stability and Oxygen Defect Chemistry of Pyrochlore and Related High-Performing Electrocatalysts for Oxygen Evolution Reaction

NSF-DFG Echem：烧绿石及相关高性能析氧反应电催化剂的表面稳定性和氧缺陷化学

• 批准号: 460551908
• 负责人: Professor Dr. Andreas Klein
• 金额: --
• 依托单位: Department of Chemistry
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/460551908?language=en
• 关键词: NSF; DFG; Echem; Surface; Stability

It is hypothesized that the surface Fermi energy is an important descriptor for a high activity and stability of noble-metal free electrocatalytic materials. To test this hypothesis, the project will study the Fermi energy position at the surfaces of pyrochlore electrocatalysts such as Y2Ru2O7 and RE2Ru2O7 (RE = Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) for the oxygen evolution reaction in aqueous electrolytes using X-ray photoelectron spectroscopy with in situ sample processing. Interface formation with high and low work function oxides, such as RuO2 and Sn-doped In2O3 (ITO), as well as oxidizing and reducing treatments will be employed to assess the energy band alignment of the electrocatalysts in conjunction with the limits of the surface Fermi energy. The limitation of the Fermi energy is related to valence changes of the Ru ions and determines the thermodynamic stability range of the catalysts in contact with the electrolyte. A potential enhancement of stability and activity by confining the Fermi energy at the surface using suitable dopants will be assessed. The project is part of a joint NSF-DFG proposal under the lead of University of Illinois at Urbana-Champaign, where Prof. Hong Yang is responsible for sample synthesis and electrocatalytic characterization and Prof. Nicola H. Perry for defect chemistry analysis. The results obtained from the XPS analysis will be compared with defect properties and be used to develop composition and doping concepts for stable and highly active pyrochlore photocatalysts. By this, the project will advance water-splitting technology for low temperature polymer electrolyte membrane (PEM)-based electrolyzers.

表面费米能是表征无贵金属电催化材料高活性和稳定性的重要指标。为了验证这一假设，该项目将利用X射线光电子能谱和原位样品处理技术，研究烧绿石电催化剂Y2Ru2O7和RE2Ru2O7(RE=Pr，ND，Sm，Eu，Gd，Tb，Dy，Ho，Er，Tm，Yb和Lu)在水溶液中析氧反应的费米能量位置。我们将采用高功函数氧化物和低功函数氧化物(如RuO2和掺锡In_2O_3(ITO))的界面形成，以及氧化和还原处理来结合表面费米能量的限制来评估电催化剂的能带排列。费米能的极限与Ru离子的价态变化有关，并决定了催化剂与电解液接触的热力学稳定范围。通过使用合适的掺杂剂将费米能量限制在表面，可以潜在地增强稳定性和活性。该项目是由伊利诺伊大学香槟分校(University of Illinois at Urbana-Champaign)牵头的NSF-DFG联合提案的一部分，杨鸿教授负责样品合成和电催化表征，Nicola H.Perry教授负责缺陷化学分析。XPS分析的结果将与缺陷性质进行比较，并用于开发稳定和高活性焦绿石光催化剂的组成和掺杂概念。通过该项目，将推进低温聚合物电解质膜(PEM)电解槽的分水技术。