Synthetic nitrogen fertilizer such as urea has been key to increasing crop productivity and feeding a growing population. However, the conventional urea production relies on energy-intensive processes, consuming approximately 2% of annual global energy. Here, we report on a more-sustainable electrocatalytic approach that allows for direct and selective synthesis of urea from nitrate and carbon dioxide with an indium hydroxide catalyst at ambient conditions. Remarkably, Faradaic efficiency, nitrogen selectivity and carbon selectivity reach 53.4%, 82.9% and ~100%, respectively. The engineered surface semiconducting behaviour of the catalyst is found to suppress hydrogen evolution reaction. The key step of C–N coupling initiates through the reaction between *NO₂ and *CO₂ intermediates owing to the low energy barrier on {100} facets. This work suggests an appealing route of urea production and provides deep insight into the underlying chemistry of C–N coupling reaction that could guide sustainable synthesis of other indispensable chemicals.

尿素等合成氮肥一直是提高作物生产力和养活不断增长的人口的关键。然而，传统的尿素生产依赖于能源密集型过程，每年消耗全球能源的约 2%。在这里，我们报告了一种更可持续的电催化方法，该方法允许在环境条件下使用氢氧化铟催化剂从硝酸盐和二氧化碳中直接和选择性地合成尿素。值得注意的是，法拉第效率、氮选择性和碳选择性分别达到 53.4%、82.9% 和 ~100%。发现催化剂的工程表面半导体行为抑制析氢反应。C-N偶联的关键步骤是通过*NO ₂和*CO ₂之间的反应启动的由于 {100} 面上的低能垒，中间体。这项工作提出了一条有吸引力的尿素生产路线，并提供了对 C-N 偶联反应的潜在化学的深入了解，可以指导其他必不可少的化学物质的可持续合成。