中国科学院福建物构所王要兵团队报道了鞣花酸基共价有机框架的高效光催化CO₂还原。相关研究成果于2024年5月30日发表于国际顶尖学术期刊《美国化学会杂志》。

将共价有机框架（COFs）用于光催化CO₂还原反应（CDRR）以产生高价值的化学燃料，并减少温室气体排放是一种可持续的催化转化方法。然而，实现优异的光催化CDRR性能受到与COFs相关的低电荷分离效率、差稳定性和高制备成本的挑战的阻碍。

该文中，研究人员利用全氟金属酞菁（MPcF16）和有机生物分子化合物鞣花酸（EA，）作为构建块来制备名为EPM-COF（M=Co，Ni，Cu）的功能共价有机框架（COFs）。设计的EPCo-COF以钴金属活性位点为特征，在光催化CO₂还原反应（CDRR）中表现出令人印象深刻的CO生成速率和选择性。

此外，经过碱处理（EPCo-COF-AT）后，COF暴露出羧酸阴离子（COO^-）和羟基（OH），从而增强EA的给电子能力。这种改性提高了17.7 mmol g^–1 h^–1的CO产率，在高效光催化CDRR中具有97.8%的卓越CO选择性。理论计算进一步表明，用COO^–和OH功能化的EPCo-COF-AT可以有效缓解CDRR过程中涉及的能垒，这有助于质子耦合电子转移过程，并提高EPCo-COF-AT中钴活性位点的光催化性能。

附：英文原文

Title: Efficient Photocatalytic CO2 Reduction in Ellagic Acid–Based Covalent Organic Frameworks

Author: Wan Lin, Fuwen Lin, Jing Lin, Zhiwei Xiao, Daqiang Yuan, Yaobing Wang

Issue&Volume: May 30, 2024

Abstract: Employing covalent organic frameworks (COFs) for the photocatalytic CO2 reduction reaction (CDRR) to generate high-value chemical fuels and mitigate greenhouse gas emissions represents a sustainable catalytic conversion approach. However, achieving superior photocatalytic CDRR performance is hindered by the challenges of low charge separation efficiency, poor stability, and high preparation costs associated with COFs. Herein, in this work, we utilized perfluorinated metallophthalocyanine (MPcF16) and the organic biomolecule compound ellagic acid (EA) as building blocks to actualize functional covalent organic frameworks (COFs) named EPM-COF (M = Co, Ni, Cu). The designed EPCo-COF, featuring cobalt metal active sites, demonstrated an impressive CO production rate and selectivity in the photocatalytic CO2 reduction reaction (CDRR). Moreover, following alkaline treatment (EPCo-COF-AT), the COF exposed carboxylic acid anion (COO–) and hydroxyl group (OH), thereby enhancing the electron-donating capability of EA. This modification achieved a heightened CO production rate of 17.7 mmol g–1 h–1 with an outstanding CO selectivity of 97.8% in efficient photocatalytic CDRR. Theoretical calculations further illustrated that EPCo-COF-AT functionalized with COO– and OH can effectively alleviate the energy barriers involved in the CDRR process, which facilitates the proton-coupled electron transfer processes and enhances the photocatalytic performance on the cobalt active sites within EPCo-COF-AT.

DOI: 10.1021/jacs.4c04185

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c04185