铁族金属磷基纳米材料制备及催化析氢研究

Iron-group metal phosphides and phosphorus alloys are promising cheap and abundant nonprecious hydrogen evolution catalysts for hydrogen generation from water electrolysis. In this program, focusing on iron-group metal (e.g., Fe, Co, and Ni) phosphorus-based hydrogen evolution catalysts, we will exploit controllable preparation strategies to obtain nanomaterials with high purity, small particle size, good dispersity and large specific surface area, and test their catalytic properties. We plan to investigate the structure-properties relationship and catalytic mechanism by combining density-functional-theory (DFT) computation and experimental techniques such as electron microscopy, optical and energy spectroscopy, voltammetry, impedance, and so on. We aim to elucidate the correlation between catalytic performance and physicochemical parameters like chemical composition, crystal structure, morphology, size, crystallinity, facet exposure, alloy degree and deficiency, in order to disclose the performance-determining factors. Furthermore, we attempt to develop efficient surface-modification approaches for improving the applicability of metal phosphorus catalysts (e.g., Fe-P, Ni-P, and Co-P) in acidic and alkaline media, and also for enhancing catalytic activity and cycling stability of these materials. The goal of this program is to theoretically and experimentally enlighten the development of low-cost yet well-performing hydrogen evolution catalysts based on iron-group metal elements.

铁族金属磷化物及合金可作为低成本、来源丰富的非贵金属析氢催化剂，应用于电解水制氢。本项目将探索Fe、Co、Ni等铁族磷基纳米材料的可控制备与形貌尺寸调控，获得具有高纯度、小粒径、单分散、大比表面积等特性的纳米催化剂，测试其催化析氢性能，采用密度泛函理论计算并结合电镜、光谱、能谱、伏安、阻抗等实验分析手段，研究构效关系和催化机制，阐明本征催化活性与材料化学组成、晶体结构、形貌、尺寸、结晶度、晶面取向、合金化程度、缺陷等理化参数的关联规律，揭示影响性能的关键因素，发展有效表面修饰改性方法，拓宽Fe-P、Ni-P、Co-P等催化材料在酸碱性介质中的适用范围，提高其催化活性及循环使用稳定性，为廉价、高效铁族金属基析氢催化剂的设计和制备提供理论指导和实验依据。

电解水是制备高纯度氢气的有效方法之一，在清洁能源领域具有重要的应用前景。铁族金属及化合物作为析氢电催化剂具有低成本、来源丰富等优点。本项目围绕Fe、Co、Ni等铁族磷基纳米材料的可控制备及电催化析氢性能开展研究，主要研究内容和结果包括：（1）采用自模板法及固相磷化法制备出多孔多壳式磷化镍空心微球结构，碱性介质中10 mA/cm2电流密度析氢过电位仅需98 mV，全解水电压为1.57 V，结合电化学和原位光谱等方法揭示原位生成的Ni2P/NiOOH异质结构为析氧活性中心。（2）提出了含氧酸阴离子辅助阴极还原电沉积制备高性能氢氧化物/氧化物电极材料的新方法，通过利用离子插入性质增强沉积物与基底界面结合力，利用马赛克纳米结构中Ni/Ce复合调控电子性质，同时提高电解水电极的催化活性与稳定性。（3）设计制备了系列多元非晶钴基磷化物催化剂，泡沫镍负载的超亲水Co-B-P纳米片10 mA/cm2电流密度析氢过电位低至42 mV，系统研究了形貌、组成对催化性能的影响，揭示了Co/B/P三元组分对氢吸附能优化、金属活性位点保护的协同作用机制。本项目研究结果可为新型高效铁族金属磷化物电解水制氢催化剂的设计、制备和应用提供一定借鉴参考。