Electrochemical carbon dioxide reduction reaction (CO₂RR) is a key to achieving practical renewable energy conversion and storage as well as green chemical productions. Sn-based electrocatalysts are believed to be one of the most promising candidates for the electroreduction of CO₂ to formate. However, development of novel catalysts operating at low overpotentials with a high selectivity, large current density and high single-pass conversion of CO₂ (SPC) simultaneously remains a significant challenge. Here, we report a nanorod@sheet SnO (NRS-SnO) catalysts designed with abundant exposed Sn(II) active sites in the 2D nanosheets for high-performance electroreduction of CO₂ to formate. Formate was first reliably detected at an applied potential as low as −0.2 V (vs. RHE) and reached maximum Faradaic Efficiency (FE) of ca. 94 % at −0.7 V (vs. RHE) with a partial current density (J_HCOO-) of ca. −330 mA/cm², giving the highest cathodic CO₂-to-formate energy conversion efficiency (ca. 70 %) among known Sn catalysts for CO2RR to formate. Importantly, a high SPC of 39.3 % was achieved with the present system, proving for the first time that high SPC can be achieved for GDE based alkaline flow cell.

电化学二氧化碳还原反应（CO ₂ RR）是实现实用的可再生能源转化和存储以及绿色化工产品的关键。锡基电催化剂被认为是将CO ₂电还原为甲酸酯的最有前途的候选之一。然而，同时开发在低过电势下具有高选择性，高电流密度和高CO ₂单次转化率（SPC）的新型催化剂仍然是一项重大挑战。在这里，我们报告了一种纳米棒@SnO（NRS-SnO）催化剂，该催化剂在二维纳米片中设计有大量暴露的Sn（II）活性位点，用于高效电还原CO ₂结成队。首先在低至-0.2 V（vs. RHE）的施加电势下可靠地检测到甲酸盐，并达到约法拉第效率（FE）。94％在-0.7 V（vs.RHE）下具有部分的电流密度（j _HCOO-的）CA。-330 mA / cm ²，在已知的用于CO2RR形成甲酸的Sn催化剂中，提供最高的阴极CO ₂转化为甲酸的能量转化效率（约70％）。重要的是，本系统实现了39.3％的高SPC，这首次证明基于GDE的碱性流通池可以实现高SPC。