Modulating the Electronic Properties of Single Ni Atom Catalyst via First‐Shell Coordination Engineering to Boost Electrocatalytic Flue Gas CO2 Reduction

Abstract

Electrochemical converting CO2 to CO via single atom catalyst is an effective strategy for reducing CO2 concentration in the atmosphere and achieving a carbon‐neutral cycle. However, the relatively low CO2 concentration in industrial processes and large energy barriers for activating CO2 severely obstruct the actual application. Reasonably modulating the coordination shell of the active center is an effective strategy to enhance the activity of single atom catalysts. Herein, a well‐designed single‐atom electrocatalyst Ni‐N3S1 is developed via a large‐scale synthesis strategy. The constructed Ni‐N3S‐C exhibits a superior catalytic activity than Ni‐N4‐C for CO2 to CO conversion in H‐type cells, and the industrial‐level current density with excellent durability at a wide pH range can be achieved in gas‐diffusion flow cells. Experimental results and density functional theory (DFT) calculation demonstrate that introducing low electronegative S in an active center can significantly regulate the electronic structure of the active site, promoting the CO2 adsorption capacity and decreasing the energy barrier of *COOH formation, thus the larger size and flexibility of sulfur mitigate the nickel agglomeration and enhance the stability of Ni‐N3S‐C catalyst. This work provides an effective strategy for designing highly active single‐atom catalysts for electrocatalysis via modulating the coordination shell of reactive sites.