Angewandte Chemie, Accepted Article.
Metallic catalysts with nanopores are advantageous on improving both activity and selectivity, while the reason behind that remains unclear all along. In this work, porous Zn nanoparticles (P‐Zn) were adopted as a model catalyst to investigate the catalytic behavior of metallic nanopores. In‐situ X‐ray absorption spectroscopy, in‐situ Fourier transform infrared spectroscopy and density functional theory (DFT) analyses reveal that the concave surface of nanopores works like a pincer to capture and clamp CO 2 and H 2 O precursors simultaneously, thus lowering the energy barriers of CO 2 electroreduction. Resultantly, the pincer mechanism endows P‐Zn with a high Faradic efficiency (98.1%) towards CO production at the potential of ‐0.95 V vs. RHE. Moreover, DFT calculation demonstrates that Co and Cu nanopores exhibit the pincer behavior as well, suggesting that this mechanism is universal for metallic nanopores.