Creating High Regioselectivity by Electronic Metal–Support Interaction of a Single-Atomic-Site Catalyst

Abstract

Ligands are the most commonly used means to control the regioselectivity of organic reactions. It is very important to develop new regioselective control methods for organic synthesis. In this study, we designed and synthesized a single-atomic-site catalyst (SAC), namely, Cu1-TiC, with strong electronic metal–support interaction (EMSI) effects by studying various reaction mechanisms. π cloud back-donation to the alkyne on the metal catalytic intermediate was enhanced during the reaction by using transient electron-rich characteristics. In this way, the reaction achieved highly linear-E-type regioselective conversion of electronically unbiased alkynes and completely avoided the formation of branched isomers (ln:br >100:1, TON up to 612, 3 times higher than previously recorded). The structural elements of the SACs were designed following the requirements of the synthesis mechanism. Every element in the catalyst played an important role in the synthesis mechanism. This demonstrated that the EMSI, which is normally thought to be responsible for the improvement in catalytic efficiency and durability in heterogeneous catalysis, now first shows exciting potential for regulating the regioselectivity in homogeneous catalysis.

Electronic Metal‐Support Interaction Directing the Design of Fe(III)‐Based Catalysts for Efficient Advanced Oxidation Processes by Dual Reaction Paths

“…[21] The EMSI can be used not only to stabilize the metal species but also to modulate the metal d-band centers by causing substantial electronic perturbations. [22][23][24][25][26][27][28][29][30] Our previous study also confirmed that EMSI can modulate the charge density of Au atoms, presenting positively charged Au + while containing charge accumulation area. [8] Therefore, tailoring the EMSI by rational coordination of Fe(III) to the support is an effective and versatile way to turn the electrons on the d orbitals of the Fe(III) into an "activation" mode, thus promoting the electron transfer.…”

Single-atom catalysts: stimulating electrochemical CO2 reduction reaction in the industrial era

“…Different from the characteristics of inert carbon substrates, nanocrystals typically have high catalytic activity, which modify the single metallic atoms at the interface and can regulate the local electron density at the active centers. [73][74][75][76][77][78] The impregnation method is a general strategy to synthesize nanocrystal/cluster-supported SACs, which is different from carbon-supported SACs, where galvanic replacement (GR) 79,80 and cation/anion exchange reaction 81,82 can occur on nanocrystals/clusters. Zheng et al developed a method to deposit single Pd atoms on the (100) and (110) facets of Cu nanocrystals through a GR reaction.…”

Low‐dimensional material supported single‐atom catalysts for electrochemical CO2 reduction

“…Single-atom catalysis, a concept proposed by Zhang et al, 11 has been spread in recent years. Single-atom catalysts (SACs) have been widely studied in various reactions, including organic catalysis, [12][13][14][15][16][17] environmental catalysis, 18 oxygen reduction reaction, [19][20][21][22][23][24] water splitting, [25][26][27] hydrogen oxidation reaction, 28 nitrogen reduction reaction, 29,30 lithium-sulfur batteries, 31 formic acid oxidation, 32,33 ethanol electro-oxidation reaction, 34,35 as well as ECR. [36][37][38][39][40][41] This is mainly because the SACs with unsaturated coordination configurations and maximized metal usage endow them with descent activity and selectivity in those reactions.…”