Dual‐Site Functionalization on Supported Metal Monolayer Electrocatalysts for Selective CO₂ Reduction

Abstract Development of efficient catalysts for electrochemical carbon dioxide reduction reaction (CO₂RR) represents a great challenge in renewable energy research. Although noble metals have long been explored as catalysts for CO₂RR, their reactivity and selectivity remain rather low owing to the competing hydrogen evolution reaction (HER). Here, this work proposes that noble metal monolayers (MLs) supported by transition metal carbides (TMCs) and nitrides (TMNs) can become exceptional CO₂RR catalysts with much suppressed HER. This work shows that there is a direct, antibonding interaction between the hydrogen adsorbate and the TMC/TMN substrates, while such interactions between CO₂RR intermediates and the substrates are absent. This difference enables dual‐site functionalization of the ML catalysts, which circumvents the energy scaling relations dictating the competition between CO₂RR and HER. Consequently, it is possible to reduce the binding of the H adsorbate to suppress HER and simultaneously increase the binding of CO₂RR intermediates to boost the CO₂RR. This work identifies several Ag and Au‐based catalysts that are thermodynamically and electrochemically stable and exhibit high activity and selectivity toward the production of formic acid. In addition, this work predicts that higher order CO₂RR products including methanol and ethylene can also be produced on selected catalysts.