Heteroatoms Induce Localization of the Electric Field and Promote a Wide Potential‐Window Selectivity Towards CO in the CO2 Electroreduction

Abstract Carbon dioxide electroreduction (CO 2 RR) is a sustainable way of producing carbon‐neutral fuels. Product selectivity in CO 2 RR is regulated by the adsorption energy of reaction‐intermediates. Here, we employ differential phase contrast‐scanning transmission electron microscopy (DPC‐STEM) to demonstrate that Sn heteroatoms on a Ag catalyst generate very strong and atomically localized electric fields. In situ attenuated total reflection infrared spectroscopy (ATR‐IR) results verified that the localized electric field enhances the adsorption of *COOH, thus favoring the production of CO during CO 2 RR. The Ag/Sn catalyst exhibits an approximately 100 % CO selectivity at a very wide range of potentials (from −0.5 to −1.1 V, versus reversible hydrogen electrode), and with a remarkably high energy efficiency (EE) of 76.1 %.