纳米化氧心三核簇基金属有机框架电催化二氧化碳还原研究

The conversion of carbon dioxide into fuels or high value-added chemicals is of great significance for alleviating energy crisis and environmental problems. The synthesis of highly active catalysts are the key to carbon dioxide conversion. Metal organic framework materials are a promising kind of electrocatalysts for carbon dioxide reduction. However, the current MOF materials used for electrocatalytic carbon dioxide reduction are mainly constructed by single metal ions. These MOF catalysts suffer from problems such as high overpotential, low stability, and difficulty in precise product selectivity. Therefore, the development of MOF materials with better catalytic performance is desired. Compared with the mononuclear metal ion-structured MOF, the oxygen-core trinuclear cluster-based MOF has the characteristics of excellent structural stability, strong metal ion tunability and multi-metal coupling synergistic effect, which theoretically can ameliorate the problems. In addition, the nanocrystallization of the oxygen-core trinuclear cluster-based MOF can improve its conductivity, electrochemical activity specific surface area and solution permeability, thereby further enhancing its electrocatalytic carbon dioxide reduction activity. This project is to study the carbon dioxide reduction performance of nanoscale oxygen-core trinuclear cluster-based MOF electrocatalysts for the first time, and to prepare MOF materials with better electrocatalytic carbon dioxide reduction performance by regulating metal ions and organic ligands.

将二氧化碳转化成燃料或高附加值的化学制品，对缓解能源危机和环境问题具有十分重要的意义。高性能催化剂是实现二氧化碳还原转化的关键。金属有机框架材料是一类具有前景的二氧化碳还原电催化剂。然而，当前用于电催化二氧化碳还原的MOF材料主要是由单金属离子构筑的，这些MOF催化剂遭遇过电位较高、稳定性较低以及产物选择性难以精准调控等问题。因此发展催化性能更为优异的MOF材料迫在眉睫。与单核金属离子构筑的MOF相比，氧心三核簇基MOF具有结构稳定性好，金属离子可调性强以及多金属耦合协同效应的特点，理论上将能改善当前MOF催化剂遭遇的问题。此外，氧心三核簇基MOF的纳米化能提高其导电性、电化学活性比表面积以及溶液渗透性，从而进一步提升其电催化二氧化碳还原活性。本项目拟首次研究纳米化氧心三核簇基MOF电催化二氧化碳还原性能，并通过调控金属离子以及有机配体制备出拥有更优电催化二氧化碳还原性能的MOF材料。

将CO2转化成燃料或高附加值的化学制品，不仅能够减轻人类社会对传统化石资源的依赖，而且还能够降低大气中CO2含量，对缓解能源危机和环境问题具有十分重要的意义。高性能催化剂是实现二氧化碳还原转化的关键。此外，一个完整的二氧化碳还原装置是由阳极和阴极构成，其中阴极是二氧化碳还原反应（CO2RR），阳极则是氧气析出反应（OER），因此高活性OER催化剂的研发对于二氧化碳还原的高效进行也非常关键。本项目利用Bi基MOF作为催化剂或预催化剂，实现了Bi基催化剂催化CO2还原活性和选择性的显著提升。一方面，我们揭示了MOF中真正的CO2还原催化活性位点。另一方面，我们证明了有机小分子对Bi活性位点的增强作用。这一研究不仅阐述了有机配体调控和催化性能之间的关系，且证实了Bi基MOF在电催化CO2转化为HCOOH中的巨大潜力。此外，我们还通过有机硒调控金属活性位点用于高效OER，不仅阐述了有机硒调控和催化性能之间的关系，而且还证明了分子增强催化这一概念在实现高效且经济地生产高附加值化学品中的巨大潜力。