Spatially separated single atom/nanaoparticle dual sites on porous carbon for synergistic electrochemical CO₂ reduction to syngas

Electrochemical CO₂ reduction reaction (CO₂RR) to syngas represents a promising strategy to mitigate CO₂ emission and achieve carbon neutrality. Dual-site metal catalysts have emerged as an effective candidates for syngas production, however, challenges such as limited catalytic activity and inadequate control over the H₂/CO ratio persist. Herein, a spatially separated dual-site catalyst containing cobalt phthalocyanine (CoPc) and ∼18 nm hollow Co₃O₄ nanoparticles (NPs) was developed, in which CoPc and Co₃O₄ are confined outside and inside the N-doped carbon (N–C) support, respectively. Experimental and calculation analyses reveal that the CoPc sites promote CO production, while the Co₃O₄ NPs are responsible for H₂ production. The strong electronic coupling effect among CoPc, N–C and Co₃O₄ NPs optimizes the electronic structure of catalyst and modulates the adsorption behaviors of reaction intermediates, leading to superior catalytic performance. A consistent H₂/CO ratio of 2:1 is achieved across an extensive potential window ranging from −0.6 to −1.1 V vs. RHE, which is highly advantageous for industrial applications. Furthermore, adjustments in catalyst composition and microenvironment enable precise tuning of the H₂/CO ratio from 1 to 2. This study provides a straightforward approach to designing dual-site catalysts for efficient syngas production.