基于多酸基杂化物的双金属催化剂的设计、构筑及其电催化析氢研究

The highly active and stable catalyst in hydrogen evolution reaction (HER) is crucial for water electrolysis for hydrogen production, which have received extensive attention to address the energy and environmental crisis. Currently there are many challenges in preparing HER catalysts, such as expensive raw materials, complicated synthesis methods and unattainable HER activity and stability under wide pH range. To resolve above-mentioned problems, the proposed project aims to obtain non-noble metal HER catalysts with bimetallic active sites and hierarchical porous structure. To obtain these HER catalysts, POM-based MOF materials (POMOFs) serve as template, firstly coated with polymers to form "core-shell" nanostructures, which are further treated with one-step pyrolysis. Their catalytic performance for hydrogen evolution reaction will be systematically investigated in acidic and alkaline solution through pre-design of electrocatalyst, optimized control of morphology structure, performance test of catalyst properties. Besides, based on the density functional theory, the mechanism between the structure and activity of catalysts will be explored on a molecular lever. This research will lay theoretical and experimental foundation for catalytic chemistry application of non-noble metal HER catalysts based applying POMOFs as template, meanwhile, providing novel methods for enhancing catalytic activity and stability of the catalysts in wide pH range.

高活性、高稳定性的析氢(HER)催化剂是水电解制氢过程中的核心，是解决能源和环境问题的研究热点。目前HER催化剂存在诸多挑战，例如昂贵的原材料、复杂的合成方法以及全pH值下的HER活性和稳定性。为克服这些瓶颈问题，本项目提出采用多酸基金属有机骨架材料(POMOFs)为模板，外层包裹聚合物形成“核-壳”纳米结构，通过一步热解法制备出多级孔共存、具有双金属活性位点的非贵金属析氢催化剂。通过催化剂材料的预先设计，形貌结构的优化调控，催化剂材料的性能测试，系统研究这类材料在不同酸碱条件下析氢方面的催化性能。同时基于密度泛函理论，从分子水平上揭示催化剂结构与活性之间的催化机理。预计可为POMOFs模板法制备非贵金属析氢材料在催化化学方面的应用提供实验和理论基础，并为催化剂在不同pH下保持高催化活性和稳定性提供新的解决思路。

电解水析氢材料的发展对实现氢能源作为绿色能源替代化石燃料具有重要的现实意义。围绕目前电解水析氢催化剂存在诸多挑战，例如复杂的合成方法以及不同pH值下的HER活性和稳定性，本项目拟以多金属氧酸盐、过渡金属和聚合物为前驱体，通过简单一步热解得到具有分级多孔结构的非贵金属析氢催化剂。研究结果达到了预期目标，取得的主要创新成果如下：以PMo12、NH4Cl和葡萄糖为前驱体，通过一步简单、可扩展的糖吹方法获得Gb-Mo2C@P催化剂；采用聚苯胺作为软模板，通过高温煅烧和PH3磷化过程制备碳包覆的单金属(Co2P@C)催化剂；采用室温机械研磨法制备PMo12@ZIF-8/ZnO，然后以其为前驱体合成氮掺杂分层多孔石墨碳包覆的纳米碳化钼催化剂(MoC@NC)；以聚乙烯亚胺、多金属氧酸盐和金属离子为前驱体，通过软模板制备了一种低成本多孔双金属杂化电催化剂(Ni/Mo6Ni6C@C)。各类催化剂实现了合成方法简单性和在不同酸碱条件下的HER活性和稳定性。其中采用密度泛函理论（DFT）对制备的催化剂Ni/Mo6Ni6C@C进行了氢吸附自由能、电荷密度差、态密度和应力曲线的模拟，进一步解释催化机理。这些研究成果有望为催化剂在不同pH下保持高催化活性和稳定性提供新的解决思路。