瑞士苏黎世联邦理工学院Ruth Signorell团队提出了尿素在水滴中由二氧化碳和氨自发形成。相关论文发表在2025年6月26日出版的《科学》杂志上。

尿素是寻找生命起源的关键分子，也是工业大量生产的基本化学物质。由氨和二氧化碳形成尿素需要高压和高温，在较温和的条件下亦可形成，但需要催化剂或额外的试剂。

研究组观察到在环境条件下，氨和二氧化碳在水滴表层自发形成尿素。利用拉曼光谱带作为标记探测了单个光学捕获的液滴。研究组发现表层就像一个微观流动反应器，化学梯度提供了一种非常规反应途径。该观察揭示了独特液滴化学的通用机理方案。界面化学是益生元条件下尿素生成的一种可能的非能量途径。

附：英文原文

Title: Spontaneous formation of urea from carbon dioxide and ammonia in aqueous droplets

Author: Mercede Azizbaig Mohajer, Pallab Basuri, Andrei Evdokimov, Grégory David, Daniel Zindel, Evangelos Miliordos, Ruth Signorell

Issue&Volume: 2025-06-26

Abstract: Urea is a key molecule in the search for the origin of life and a basic chemical produced in large quantities by industry. Its formation from ammonia and carbon dioxide requires either high pressures and temperatures or, under milder conditions, catalysts or additional reagents. In this study, we observed the spontaneous formation of urea under ambient conditions from ammonia and carbon dioxide in the surface layer of aqueous droplets. Single, optically trapped droplets were probed by using Raman bands as markers. We found the surface layer to act like a microscopic flow reactor, with chemical gradients providing access to unconventional reaction pathways. This observation revealed a general mechanistic scheme for distinctive droplet chemistry. Interfacial chemistry is a possible nonenergetic route for urea formation under prebiotic conditions.

DOI: adv2362

Source: https://www.science.org/doi/10.1126/science.adv2362