Industry‐Level Electrocatalytic CO2 to CO Enabled by 2D Mesoporous Ni Single Atom Catalysts

Abstract Electrocatalytic CO 2 reduction reaction (eCO 2 RR) has captivated widespread attentions, yet achieving the requisite efficiency, selectivity and stability for industrial applications poses a persistent challenge. Here, we report the synthesis of 2D mesoporous Ni single atom catalysts in N‐doped carbon framework via a bottom‐up interfacial assembly strategy. The 2D mesoporous Ni−N−C catalyst showcases an ultrathin thickness (~6.7 nm) with well‐distributed 5 to 40 nm‐width mesopores in plane and a high surface area. As a result, the Ni single atom sites with a high density (~6.0 wt %) are almost completely exposed and can be accessible, and the mass transfer can be greatly promoted even at high current densities. Thus, a high current density of 446 mA cm −2 with >95 % CO selectivity in a flow cell can be obtained. Concurrently, the catalyst demonstrates an impressive stability, maintaining a 50‐hours continuous electrolysis in the membrane electrode assembly test and achieving an energy efficiency of 42 %. Finite element analysis reveals that the 2D mesoporous design enhances CO 2 diffusion, ensuring efficient adsorption and swift CO desorption at high current densities. Our study paves a way for the fabrication of 2D mesoporous single atom catalysts with nearly 100 % accessibility and expedited mass transport.