铁在催化活性位中的作用 - FeN/C与CNx的活性位结构对氧还原活性和稳定性的影响研究

项目名称： 铁在催化活性位中的作用 - FeN/C与CNx的活性位结构对氧还原活性和稳定性的影响研究

项目编号： No.21506041

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 有机化学

项目作者： 田娟

作者单位： 贵州师范大学

项目金额： 21万元

中文摘要： 低价、高效的氧还原（ORR）非贵金属催化剂（NPMCs）是质子交换膜燃料电池研究的热点。FeN/C已在活性上取得突破，但稳定性仍是难点；CNx有较好的稳定性但活性较差。这两类催化剂的催化活性位有不同结构，铁在其中的作用是解开催化剂ORR活性与稳定性差异的关键。项目将在制备FeN/C与CNx催化剂的基础上，对催化剂各组分前躯体及制备方法进行考察，优化制备方法；利用电化学方法测试催化剂的ORR活性和稳定性，分析其ORR动力学特性；利用探针分子或毒物分子（CO，氰化物，硫化物等）研究活性位中铁的价态和存在形态；利用物性和光谱表征方法（如TGA, BET, XRD, XPS, TEM, Mossbauer谱等）对催化剂的结构进行表征；结合电化学与物性和光谱表征结果，探索研究催化剂中催化活性位的组成、结构与活性、稳定性之间的关系，为高稳定、高活性的NPMCs的设计制备提供理论指导。

中文关键词： 非贵金属催化剂；氧还原反应；催化活性位；催化活性；稳定性

英文摘要： Non-precious metal catalysts (NPMCs) have attracted great attention due to their low cost and high activity toward oxygen reduction reaction (ORR). Recent studies showed FeN/C catalysts have high initial ORR activity close to the level of platinum based catalysts, However, it demonstrated poor durability. In parallel, CNx showed good durability but poor initial activity. These two types of catalysts have different active site structure and the role of Fe in active sites is the key parameter to find the differences between FeN/C and CNx, which the key factor to prepare ORR catalysts with high activity and stability. In this project, we will design and prepare NPMCs with high activity and durability for ORR in proton exchange membrane fuel cells (PEMFCs). The proposed work will undertake an investigation of the nature of active sites, and the degradation mechanism for ORR in NPMCs using fundamental approaches based on catalysis and electrochemistry. The main objective is arriving at a molecular level understanding of the electrocatalytic phenomena involved in the ORR over NPMCs. The nature of the active sites and the ways to create these active sites for ORR will be investigated in an effort to control electrocatalytic properties by molecular tailoring of the catalyst nanostructure and its surface moieties. Catalysts will be characterized using an array of techniques to acquire information about their physical characteristics (surface area, pore size distribution, particle diameter, crystal structure, crystal plane exposure, defects, etc.), and structural and molecular characteristics. Activity and durability measurements will be performed using kinds of electrochemical techniques. Experimental work will be closely coupled with modeling studies to provide a molecular-level understanding of the factors that contribute to the activity and durability in NPMCs for ORR. The practical relevance of the works in this project lies in the need for developing NPMCs for ORR in PEMFCs and the long-term objectives include building a knowledge base that would facilitate the production of active, stable and inexpensive cathode electrocatalysts that would realize the wide-spread application of fuel cells for energy generation.

英文关键词： Non-precious metal catalyst;Oxygen reduction reaction;Catalytic acitve site;Catalytic activity;Durability