含磺酸根配位基团的钌水氧化催化剂的设计、合成和性能研究

Environmental issues and energy crisis are the most serious problems that human beings have encountered in this century. Artificial photosynthesis, which is a hot research topic currently in the renewable energy field, holds the promise to solve these obstacles. One of the critical components of the artificial photosynthesis devices or water splitting devices is catalysts that directly influence the performance and stability of these devices. Many molecular water splitting devices have been constructed and studied for water oxidation and total water splitting. Unfortunately, all these molecular water splitting devices encountered stability issues, especially the stability of the catalyst. Therefore, there is an urgent request on the development of efficient water oxidation catalysts with outstanding long lifetime under the catalytic conditions. On the basis of previous research results, we noticed that our highly effective Ru water oxidation catalysts with negatively charged, carboxylate-containing ligands underwent ligand dissociation and resulted in short lifetime. Through careful design, we propose in this project to introduce sulfonate coordination group and replace the carboxylate group, with a view to reducing the ligand dissociation and improving the lifetime of Ru-based water oxidation catalysts. Electrochemistry, kinetics, isotopic labelling experiments etc. will be conducted to illustrate the reaction mechanisms of the target Ru water oxidation catalysts. Through systematic structural modification, the structure-reactivity relationship will be revealed. According to their reaction mechanisms, the structures of a few Ru water oxidation catalysts will be tailored to enhance the reactivity of the rate limiting step, resulting in effective water oxidation catalysts with outstanding stability under the catalytic conditions.

人工光合作用是近年来可再生能源研究的前沿课题之一。催化剂是构建人工光合作用器件（光解水器件）的关键组成部分，该组分的稳定性直接影响到器件的性能和稳定性。目前为止，许多光解水分子器件所使用的分子型水氧化催化剂都存在使用寿命短这样的弊端。因此，解决催化剂的寿命问题刻不容缓。本项目基于已有工作基础，针对一些含羧酸配体的、高效的钌水氧化催化剂配体容易解离、催化寿命短的问题，通过研究催化剂失活机理，合理地引入磺酸根替换羧酸根来构建一系列钌水氧化催化剂，利用磺酸根的结构特性来减少催化剂骨架配体的解离，提高催化剂的使用寿命。利用电化学、动力学分析、同位素示踪等手段研究催化剂的催化特性，阐述催化机理。通过系统的结构修饰，研究催化剂结构与催化活性和寿命之间的关系，为新一代的催化剂开发奠定基础。

催化剂是构建人工光合作用器件（光解水器件）的关键组成部分，该组分的稳定性直接影响到器件的性能和稳定性。目前为止，许多光解水分子器件所使用的分子型水氧化催化剂都存在使用寿命太短这样的弊端。本项目针对一些含羧酸配体的、高效的钌水氧化催化剂配体容易解离、催化寿命短的问题展开研究，在过去的四年里，项目按照计划实施，除了少部分难题未能解决之外大部分研究内容都得以顺利实施，并取得了一系列的创新性成果，在PNAS、Angew. Chem. Int. Ed.、Nature Communications、Chinese Journal of Chemistry、ACS Catalysis、Inorganic Chemistry等发表论文18篇，申请发明专利1项，授权实用新型发明专利1项；培养研究生8名（其中1人已经毕业）。所取得的的成果包括：（1）通过研究催化剂失活机理，合理地引入磺酸根和硫代羧酸根配体替换羧酸根配体来构建一系列钌水氧化催化剂，利用磺酸根和硫代羧酸根的结构特性来减少催化剂骨架配体的解离，提高催化剂的使用寿命。（2）利用电化学、动力学分析、同位素示踪等手段研究催化剂的催化特性，阐述催化机理。通过系统的结构修饰，研究催化剂结构和催化活性和寿命之间的关系，为新一代的催化剂开发奠定基础。（3）扩展了项目研究内容，研究表面配位型单原子催化剂催化小分子活化反应，将石墨双炔负载的单原子催化剂和氮掺杂石墨烯负载的单原子催化剂用于氮气活化反应。