中国科学院福建物构所黄远标团队报道了，二维硫醇基导电金属有机框架上引导二氧化碳电还原为碳氢化合物。相关研究成果发表在2025年1月22日出版的《科学通报》。

几乎所有的Cu_xS化合物都只产生简单的双电子转移产物CO和HCOOH，但在电催化CO₂还原反应（CO₂RR）中获得多电子转移的烃产物仍然是一个巨大的挑战。此外，确定S原子对催化作用的不同贡献，特别是对电催化CO₂RR中的催化活性和产物选择性的贡献，仍然是一项具有挑战性的任务。

该文中，研究人员介绍了一种基于具有确定Cu-S₄活性位点的导电二维金属有机框架的模型催化剂，用于CO₂RR，称为Cu₃(THT)₂（THT=2,3,6,7,10,11-六硫基苯）。与主要产生常见双电子转移产物CO（40%选择性）的，具有Cu-N₄基序的前体催化剂Cu₃(HITP)₂不同，Cu₃(THT)₂将初级产物转化为深度还原产物CH₄。

在1.4 V vs. RHE下，Cu₃(THT)₂对CH₄的法拉第效率为63.5%，电流密度高达298.3 mA cm^-2。理论研究表明，富电子的Cu-S₄位点比Cu-N₄位点更有效地稳定和激活关键中间体*CO。此外，S原子可以接受电子并与*CO形成弱S···O相互作用，为*CO提供额外的稳定性。

该项研究首次表明，催化金属位点周围的非金属S中心，可以显著提高和调节CO₂RR中的产物选择性。

附：英文原文

Title: Steering CO2 electroreduction to hydrocarbons over 2D thiol-based conductive metal-organic framework

Author: Yuan-Biao Huang a b c

Issue&Volume: 2025/01/22

Abstract: Almost all of CuxS compounds only produce the simple two-electron transferred products CO and HCOOH but it remains a large challenge to obtain the multiple-electron transferred hydrocarbon products in electrocatalytic CO2 reduction reaction (CO2RR). Moreover, identifying the distinct contributions of S atoms to catalysis, particularly for catalytic activity and product selectivity in electrocatalytic CO2RR, remains a challenging task. Herein, we introduce a model catalyst based on a conductive two-dimensional metal-organic framework with defined Cu-S4 active sites, named Cu3(THT)2 (THT = 2,3,6,7,10,11-hexathiotriphenylene) for CO2RR. Unlike the precursor catalyst Cu3(HITP)2 with Cu-N4 motifs that predominantly produce common two-electron transferred product CO (40% selectivity), Cu3(THT)2 shifts the primary product to deep reduction product CH4. At 1.4 V versus the reversible hydrogen electrode (RHE), Cu3(THT)2 achieves a Faradaic efficiency of 63.5% for CH4 and the current density reaches a high of 298.3 mA cm2. Theoretical studies indicate that the electron-rich Cu-S4 sites stabilize and activate the key intermediate *CO more effectively than Cu-N4 sites. Furthermore, S atoms can accept electrons and form weak S···O interactions with *CO, providing additional stabilization for *CO. This study is the first to show that non-metallic S centers around catalytic metal sites can significantly enhance and tune product selectivity in CO2RR.

DOI: 10.1016/j.scib.2025.01.033

Source: https://www.sciencedirect.com/science/article/abs/pii/S2095927325000672