Abstract：
Fabrication of efficient heterogeneous catalysts with high turnover frequency (TOF) is intriguing for rapid and scalable CO2 conversion under mild conditions, but it still faces some challenges due to use of some bulky and irregular supports causing inaccessible inner pores and insufficient utilization of active sites. Herein, using a unique nitrogen-doped mesoporous single-crystal carbon (named IRFC) as a host for loading Ag nanoparticles for the first time, a series of Ag/IRFC catalysts with high TOF (8.7-22.3 h-1) were facilely prepared by a novel \"impregnation and in-situ reduction\" strategy. The neat morphology and high porosity of IRFC with abundant N species, providing homogeneous surface, adequate space and anchoring sites for Ag immobilization, greatly facilitated the formation of highly-distributed ultrasmall Ag nanoparticles (2.3 nm). Meanwhile, smooth and short diffusion pathways were inherited from the ordered mesopores and small particle sizes of IRFC. Owing to these unparalleled structural features, the Ag/IRFC catalysts exhibited excellent catalytic activity, stability, and generality for mild CO2 conversion even under diluted conditions. This work not only presents a novel catalyst for mild CO2 conversion, but also brings some inspirations to designing highly efficient catalysts using well-shaped supporting nanomaterials for direct utilization of low-concentration CO2, such as flue gas.
摘要：
具有高周转频率（TOF）的高效非均相催化剂的制造对于在温和条件下快速和可扩展的CO2转化是有趣的。但它仍然面临一些挑战，由于使用一些笨重和不规则的支持，导致无法进入的内部孔和活性位点的利用不足。在这里，首次使用一种独特的氮掺杂介孔单晶碳（称为IRFC）作为负载Ag纳米颗粒的主体，通过新型的“浸渍和原位还原”策略轻松制备了一系列具有高TOF（8.7-22.3h-1）的Ag/IRFC催化剂。具有丰富N种类的IRFC的整齐形态和高孔隙率，提供均匀的表面，足够的空间和锚定位点固定银，极大地促进了高度分布的超小Ag纳米颗粒（2.3nm）的形成。同时,从IRFC的有序中孔和小粒径中继承了光滑和短的扩散途径。由于这些无与伦比的结构特征，Ag/IRFC催化剂表现出优异的催化活性,稳定性,和一般温和的CO2转化，即使在稀释条件下。这项工作不仅提出了一种用于温和CO2转化的新型催化剂，同时也为使用形状良好的负载纳米材料设计高效催化剂以直接利用低浓度CO2，例如烟气带来了一些启示。
