水氧化功能金属有机膦酸盐骨架材料的构筑及产氧机制研究

The oxidation of water to evolve oxygen is kinetically demanding. Thus, the development of effective and robust water oxidation catalysts and elucidation of their mechanisms are of central importance to renewable energy technologies. On the basis of the above considerations, in this proposal, we will focus on the study of phosphonate-based metal-organic frameworks and develop function-oriented strategies to synthesize three types of phosphonic acid ligands. Four types of strategies were applied to construct phosphonate-based metal-organic frameworks including metal-oxygen cluster-based, bifunctional and mesoporous materials for water oxidation by reaction of phosphonic acid ligands with redox active earth-abundant transition metals. Their electrochemical and photochemical catalytic oxidation of water to dioxygen will thoroughly be studied including the correlation of activity with microscopic structural parameters, such as crystal structure, morphology, electron structure, local valence state, coordination geometry, spin states，inter-atomic interactions and so on. These results will shed light on the relationship of structure-performance and further uncover the mechanism for water oxidation catalysis, which is important for the understanding of the water oxidation mechanism in photosystem II. A new highly efficient catalyst will be developed. These works will provide a promising guideline for constructing efficient water oxidation catalysts.

水氧化析氧反应是一个缓慢的动力学过程。构建高效稳定的水氧化催化剂及理解其水氧化机理，成为可再生能源领域一个重要课题。本项目拟开展以金属有机膦酸盐晶态材料为研究对象，通过水氧化功能导向设计合成三类有机膦酸配体，采取四种策略与具有氧化还原活性的过渡金属反应构筑金属氧簇基、双功能、微孔及超薄结构的金属有机膦酸盐骨架材料。研究它们的光/电催化水分解析氧性能。系统考察晶体结构、形态、电子、价态、配位构型、自旋态、原子间相互作用等结构因素对水氧化活性的影响，揭示水氧化催化剂结构与性能之间本质联系，深入理解水氧化反应氧-氧键形成机理，研制出性能优异的水氧化催化剂。这些工作为设计高效水氧化催化剂提供实验依据与理论基础，同时，对理解自然界光系统水氧化机理具有重要的科学意义。

项目针对光/电催化水氧化的关键科学问题，以金属有机膦酸骨架材料为主要研究对象，基于项目的研究计划与研究目标，通过水氧化功能导向，设计与制备了金属氧簇基、微孔、超薄、不同形貌等金属有机膦酸盐骨架材料，系统研究了它们的水氧化性能。提出了原位电化学沉积法，构建铁、钴双金属原子掺杂的镍有机膦酸骨架材料，系统考察了电子结构对水氧化性能的影响。结合原位同步辐射与理论计算，揭示催化剂自修复机制。构筑系列配位构型不同的磷酸钴水氧化催化剂，研究了配位构型对水氧化性能的影响，揭示了柔性的磷酸基诱导表面自重构。提出配体导向策略，发现空间位阻效应诱导构建微孔结构的金属有机膦酸骨架材料，突破了传统金属有机膦酸骨架材料柱层状结构限制，揭示微孔结构对催化性能的影响。发展了磷钼酸金属氧簇为金属节点，构筑了一系钴、镍金属包含的金属氧簇基金属有机膦酸骨架材料，系统考察了它们的水氧化功能。发展模板法，探索了金属有机膦酸骨架材料形貌对水氧化性能的影响。本项目系统考察了晶体结构、形态、电子、价态、配位构型、原子间相互作用等结构因素对水氧化活性的影响，揭示水氧化催化剂结构与性能之间本质联系。项目的研究不仅对理解自然界光系统水氧化机制具有重要的科学意义，而且对指导高效水氧化催化剂设计具有重要的理论与实际意义。