Electron Penetration Effect of Ni Single Atom Boosting CO2 to CO in PH-Universal Electrolytes

Abstract

Electrocatalytic CO₂ reduction (ECR) powered by renewable electricity has attracted of wide attention because of its advantages to produce high-value-added chemicals and fuels. Additionally, ECR played a crucial role in addressing the challenge of excessive fossil fuel consumption caused by global warming. Herein, a unique armor structure with Ni nanoparticles coated by a carbon shell containing Ni─N─C (Ni─NP@Ni─SA) for industrial ECR to CO in pH-universal electrolytes is designed. Ni─NP@Ni─SA catalyst exhibits ≈100% CO Faradaic efficiency, and CO partial current density can reach 500, 361, and 615 mA cm⁻² in strong alkaline (pH 14), neutral (pH 7.2) and strong acidic (pH 1) electrolytes, respectively. Moreover, Ni─NP@Ni─SA can drive the rechargeable Zn-CO₂ battery with a high power density of 3.45 mW cm⁻², and outstanding stability over 36 h. The structural characterizations and theoretical calculation together present that the electron penetration effect of Ni─NP@Ni─SA can strengthen the electronic enrichment state of Ni single atom, which facilitates the reaction kinetics of ECR by decreasing the formation energy barrier of key intermediate ^*COOH. This work pioneers a new design strategy to enhance the activity of single-atom catalysts and seek high-efficiency electrocatalysts for ECR in pH-universal electrolytes.