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···W_SA FLP) sites are constructed for photocatalytic CO₂ conversion through introducing W single-atoms into polymeric carbon nitride. In the atomically dispersed N···W_SA 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···W_SA FLP on photocatalytic CO₂ reduction are well revealed. The N···W_SA 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.

中文翻译：

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使用 d-p 相互作用构建基于原子钨的固体 Frustrated-Lewis-Pair 位点用于选择性 CO2 光还原


由于 FLP 位点和反应物分子之间的强轨道相互作用，固体挫折路易斯对 （FLP） 在 CO₂ 等小分子的活化方面显示出显着优势。然而，目前构建的 FLP 位点大多是随机分布的，很容易在催化剂表面重新结合，导致 FLP 位点的利用率较低。在此，原子钨基 FLP （N···W_SA FLP） 位点是通过将 W 单原子引入聚合物氮化碳中来构建用于光催化 CO₂ 转化的。在原子分散的 N···W_SA FLP，缺电子的 W 单原子充当路易斯酸 （LA），相邻的富含电子的 N 原子充当路易斯碱。通过吡啶-IR、原位漫反射红外傅里叶变换光谱、CO₂ 温度程序脱附和理论计算等各种表征的组合，发现了 N···光催化 CO₂ 还原的 W_SA FLP 得到了很好的揭示。The N···W_SA FLP 可以有效地吸附 CO₂ 形成不寻常的 W-O-C-N 结构，具有显着的 d-p 轨道相互作用，这导致了有趣的“推-推”电子转移效应。从 W 5d 到 CO₂ 的反键轨道 （2π） 的π反向捐赠实现了从 W 单原子到 O 位点的反向电子转移，而电子通过路易斯酸碱相互作用从富电子的 N 位点转移到正电的 C 位点，从而有效地打破 C═O 键以激活 CO₂ 分子并提高 CO₂ 到 CO 的性能。 这项工作为基于单原子的 FLP 催化剂的高效小分子活化研究提供了一条全新的路线。