西安交通大学杨贵东团队构建具有d-p相互作用的钨基固体受挫刘易斯对原子位，用于选择性CO₂光还原。相关研究成果发表在2024年12月18日出版的《美国化学会杂志》。

固体受挫路易斯对（FLP）在激活二氧化碳等小分子方面显示出显著的优势，这是由于FLP位点和反应物分子之间的强轨道相互作用。然而，目前构建的FLP位点大多随机分布，容易在催化剂表面团聚，导致FLP位点利用率低。

该文通过在聚合物氮化碳中引入W单原子，构建了用于光催化CO₂转化的原子钨基FLP（N···WSA FLP）位点。在原子分散的N···WSA FLP中，缺电子的W单原子充当路易斯酸（LA），相邻的富电子N原子充当路易斯碱。

通过吡啶红外光谱、原位漫反射红外傅里叶变换光谱、CO₂程序升温脱附和理论计算等多种表征方法的结合，很好地揭示了N··WSA FLP对光催化CO₂还原的积极作用。N···WSA FLP可以有效地吸附二氧化碳，形成一种具有显著d-p轨道相互作用的不同寻常的W-O-C-N结构，这导致了一种有趣的“推-推”电子转移效应。

从W 5d到CO₂反键轨道（2π）的π回输实现了从W单原子到O位的反向电子转移，而电子通过路易斯酸碱相互作用从富电子的N位转移到正电性的C位，从而有效地破坏了C═O键，激活了CO₂分子，提高了CO₂到CO的性能。

该项工作为基于单原子FLP催化剂的小分子高效活化研究，提供了一条全新的途径。

附：英文原文

Title: Constructing Atomic Tungsten-Based Solid Frustrated-Lewis-Pair Sites with d-p Interactions for Selective CO2 Photoreduction

Author: Baorong Xu, Shicheng Luo, Weibo Hua, Hang Xiao, Ben Chong, Guocheng Yan, He Li, Honghui Ou, Bo Lin, Guidong Yang

Issue&Volume: December 18, 2024

Abstract: Solid frustrated Lewis pair (FLP) shows remarkable advantages in the activation of small molecules such as CO2, owing to the strong orbital interactions between FLP sites and reactant molecules. However, most of the currently constructed FLP sites are randomly distributed and easily reunited on the surface of catalysts, resulting in a low utilization rate of FLP sites. Herein, atomic tungsten-based FLP (N···WSA FLP) sites are constructed for photocatalytic CO2 conversion through introducing W single-atoms into polymeric carbon nitride. In the atomically dispersed N···WSA FLP, the electron-deficient W single-atom acts as the Lewis acid (LA), and the adjacent electron-rich N atom acts as the Lewis base. Through the combination of various characterizations, including pyridine-IR, in situ diffuse reflectance infrared Fourier transform spectroscopy, CO2-temperature programmed desorption, and theoretical calculations, the positive effects of N···WSA FLP on photocatalytic CO2 reduction are well revealed. The N···WSA FLP can effectively adsorb CO2 to form an unusual W–O–C–N structure with significant d-p orbital interactions, which leads to an interesting “push–push” electron transfer effect. The π back-donation from W 5d to the antibonding orbital (2π) of CO2 realizes reverse electron transfer from the W single-atom to the O site, while the electrons are transferred from the electron-rich N site to the electropositive C site via Lewis acid–base interactions, therefore effectively breaking the C═O bond to activate CO2 molecules and boost CO2-to-CO performance. This work provides a brand new route for the research on high-efficiency activation of small molecules based on single-atom-based FLP catalysts.

DOI: 10.1021/jacs.4c08953

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c08953