论文标题
通过空间限制的二聚体金属中心选择性C-C耦合
Selective C-C Coupling by Spatially Confined Dimeric Metal Centers
论文作者
论文摘要
将二氧化碳（CO2）直接转化为高能燃料和高价值化学物质是一种令人着迷的可持续策略。但是，对于大多数用于二氧化碳减少的电催化剂，多碳产物受到大电位和低选择性的抑制。对于实际应用，在正确操纵C-C耦合过程中，仍然存在很大的知识。本文中，我们利用分散的3D过渡金属二聚体作为空间限制的双反应中心，以选择性减少二氧化碳对液体燃料。显示各种氮的碳单层碳单层是有希望的模板，可以稳定这些金属二聚体并决定其电子结构，从而可以精确控制催化活性和产品选择性。通过综合的第一原理计算，我们筛选了合适的过渡金属二聚体，这些二聚体普遍具有乙醇活性很高（C2H5OH）。此外，发现C2H5OH的明显选择性针对锚定在C2N单层上的Fe2二聚体的其他C1和C2产品。彻底阐明了所支持金属二聚体的活性与D带中心之间的相关性以及金属二聚体与碳底物之间的电子耦合的作用。
Direct conversion of carbon dioxide (CO2) to high-energy fuels and high-value chemicals is a fascinating sustainable strategy. For most of the current electrocatalysts for CO2 reduction, however, multi-carbon products are inhibited by large overpotentials and low selectivity. For practical applications, there remains a big gap of knowledge in proper manipulation of the C-C coupling process. Herein, we exploit dispersed 3d transition metal dimers as spatially confined dual reaction centers for selective reduction of CO2 to liquid fuels. Various nitrogenated holey carbon monolayers are shown to be promising templates to stabilize these metal dimers and dictate their electronic structures, allowing precise control of the catalytic activity and product selectivity. By comprehensive first-principles calculations, we screen the suitable transition metal dimers that universally have high activity for ethanol (C2H5OH). Furthermore, remarkable selectivity for C2H5OH against other C1 and C2 products is found for Fe2 dimer anchored on C2N monolayer. The correlation between the activity and d band center of the supported metal dimer as well as the role of electronic coupling between the metal dimer and the carbon substrates are thoroughly elucidated.
