Porous Zn Conformal Coating on Dendritic‐Like Ag with Enhanced Selectivity and Stability for CO2 Electroreduction to CO

Abstract With increasing CO 2 emission and energy scarcity, electrocatalytic CO 2 reduction reaction (CO 2 RR) offers an attractive solution for CO 2 resource utilization using sustainable electrical energy. Ag‐based catalysts with high‐curvature nanoneedle structure exhibit the potential to achieve high CO 2 RR activity, but suffer from insufficient stability due to the vulnerability of the high‐curvature structure during CO 2 RR. Herein, the uniform porous Zn conformal coating on high‐curvature dendritic Ag nanoneedles (AgNNs@Zn) by vacuum thermal evaporation is prepared. As the surface sacrificial shell, the dissolution and reconstruction of Zn protect the inner Ag core, thus enhancing the CO 2 RR stability of AgNNs@Zn. The concentration of Ag + in the electrolyte after 2 h CO 2 RR electrolysis markedly reduces from 2.4 ug L −1 in AgNNs to 1.4 ug L −1 in AgNNs@Zn. Moreover, the DFT calculation reveals that the constructed Ag–Zn interfaces can stabilize the *COOH intermediates, which promote the selectivity of CO 2 reduction into CO. As a result, the optimized AgNNs@Zn catalyst exhibits the FE CO of ≈91% at −0.86 V versus RHE in H‐cell, and FE CO of 90% at 100 mA cm −2 above 12 h in flow cell. This work provides a feasible strategy to synthesize bimetallic catalysts with core–shell structure for better CO 2 RR performance.