ElectrochemicalCO₂ Reduction on SnO: Insightsinto C₁ Product Dynamic Distribution and Reaction Mechanisms

The precise synthesis of desirable products from the electrochemical CO₂ reduction reaction (CO₂RR) remains challenging, primarily due to unclear structure–activity relationships under <i>in situ</i> reaction conditions. Recognized by their cost-effectiveness and nontoxic nature, Sn-based materials are extensively utilized in CO₂RR to produce valuable chemicals. Notably, our large-scale data mining of the experimental CO₂RR literature reveals a significant trend: SnO₂-based electrocatalysts primarily generate HCOOH, while SnO-based counterparts demonstrate the ability to produce both HCOOH and CO in comparable quantities. Furthermore, our findings indicate that SnO remains underexplored in terms of its surface speciation and structure–activity relationships for the CO₂RR compared to SnO₂-based materials. Addressing these issues is crucial in the field of electrocatalysis, as understanding them will not only clarify why SnO uniquely influences the distribution of C₁ products but also provide insights into how to precisely control electrocatalytic processes for targeted product synthesis. Herein, we employed a constant-potential method combined with surface coverage and reconstruction analyses to simulate the energetics of CO₂RR intermediates and to elucidate the dynamic distribution of C₁ products on the <i>in situ</i> resting surface of SnO under typical CO₂RR conditions. Our analysis of surface coverage and reconstruction effectively identifies the active surface of SnO involved in the CO₂RR. Furthermore, comparative simulations between pristine and reconstructed SnO surfaces reveal how electrochemistry-induced oxygen vacancies direct C₁ product distribution. By addressing these critical issues, we aim to advance electrocatalysis and contribute to chemical production from CO₂, stimulating future exploration of structure–activity relationships and reaction conditions in other electrocatalytic systems.