南京师范大学兰亚乾团队开发了共价有机框架中共价链接限制和高度分散单聚金属氧酸盐团簇的策略用于CO₂光还原。相关研究成果发表在2022年1月20日出版的国际学术期刊《美国化学会杂志》。

单团簇在催化领域引起了广泛的研究兴趣。然而，实现单簇催化剂的高度均匀分散具有挑战性。

该文中，研究人员首次提出了一种在共价有机框架（COFs）中均匀分散的多金属氧酸盐（POMs）的通用策略，通过共价键将POM簇限制在COF的规则纳米孔中。这些COF-POM复合材料结合了光吸收、电子转移和合适的催化活性中心的特性；因此，它们在人工光合作用中表现出优异的催化活性：即以H₂O为电子供体的CO₂光还原。其中，在气-固反应体系中，TCOF-MnMo6的CO产率最高（37.25μmol g^–1 h^–1，选择性约为100%）。

此外，基于密度泛函理论（DFT）计算的机理研究表明，光诱导电子转移（PET）过程发生在从COF到POM的过程中，然后分别在POM和COF上发生CO₂还原和H₂O氧化。

该研究开发了一种将POM单团簇均匀分散到COF中的方法，展示了COF-POM功能材料在光催化领域的潜在应用。

附：英文原文

Title: Confining and Highly Dispersing Single Polyoxometalate Clusters in Covalent Organic Frameworks by Covalent Linkages for CO2 Photoreduction

Author: Meng Lu, Mi Zhang, Jiang Liu, Tao-Yuan Yu, Jia-Nan Chang, Lin-Jie Shang, Shun-Li Li, Ya-Qian Lan

Issue&Volume: January 20, 2022

Abstract: Single clusters have attracted extensive research interest in the field of catalysis. However, achieving a highly uniform dispersion of a single-cluster catalyst is challenging. In this work, for the first time, we present a versatile strategy for uniformly dispersed polyoxometalates (POMs) in covalent organic frameworks (COFs) through confining POM cluster into the regular nanopores of COF by a covalent linkage. These COF-POM composites combine the properties of light absorption, electron transfer, and suitable catalytic active sites; as a result, they exhibit outstanding catalytic activity in artificial photosynthesis: that is, CO2 photoreduction with H2O as the electron donor. Among them, TCOF-MnMo6 achieved the highest CO yield (37.25 μmol g–1 h–1 with ca. 100% selectivity) in a gas–solid reaction system. Furthermore, a mechanism study based on density functional theory (DFT) calculations demonstrated that the photoinduced electron transfer (PET) process occurs from the COF to the POM, and then CO2 reduction and H2O oxidation occur on the POM and COF, respectively. This work developed a method for a uniform dispersion of POM single clusters into a COF, which also shows the potential of using COF-POM functional materials in the field of photocatalysis.

DOI: 10.1021/jacs.1c11987

Source: https://pubs.acs.org/doi/10.1021/jacs.1c11987