光（电）催化氮气还原合成氨研究进展

光（电）催化氮气还原技术利用天然太阳能作为能源，具有成本低、反应条件温和等众多优势，可解决传统工业合成氨Haber-Bosch工艺的高能耗以及高CO₂排放等问题，被认为是目前最具前景的新兴合成氨技术之一。由于氮气为非极性分子，在水中溶解度极低，且本身呈现化学惰性，难以被活化，使得整体的氮气还原转化合成氨效率较低。同时，光生载流子的利用率也显著影响整体的催化效率。为此，光（电）催化氮气还原技术的关键在于催化剂的设计和催化反应体系的优化。本文在介绍光（电）催化氮气还原合成氨反应过程以及机理的基础上，主要从促进氮气溶解扩散、氮气吸附和活化以及强化载流子分离和传输等具体反应过程出发，重点综述近期国内外在光（电）催化氮气还原合成氨领域基于上述反应过程强化的最新研究现状。最后，指出了目前光（电）催化氮气还原合成氨研究领域面临的挑战，并对此领域的未来发展趋势进行了分析与展望。

Overview on photo(electro)catalytic nitrogen fixation for ammonia synthesis

Photo(electro)catalytic nitrogen reduction technology has many advantages over the traditional, well-established Haber-Bosch process for nitrogen fixation, such as the utilization of natural sun light as the energy source and significantly lower pressure and temperature to affect the reaction process. These advantages result in the use of the photo(electro)catalysis for nitrogen fixation being of lower energy cost and lower CO₂ emissions than that of the Haber-Bosch method, making it one of the most promising emerging synthetic ammonia technologies. The key to photo(electro)catalytic nitrogen fixation lies in the design of the catalyst and the optimization of the catalytic reaction system. Based on the fact that nitrogen is a non-polar molecule, has a low water solubility, and is chemically inert, it is difficult to be activated, and so the overall efficiency of nitrogen reduction to ammonia is relatively low. Increasing the utilization rate of photogenerated carriers also significantly affects the overall catalytic efficiency. This article introduces the reaction process and mechanism of photo(electro)catalytic nitrogen reduction to ammonia, mainly from the specific reaction processes of promoting the dissolution and diffusion of nitrogen, adsorption and activation of nitrogen, and enhancement of the separation and transmission of photogenerated charge carriers. Moreover, the latest research status based on the enhancement of the above reaction process in the field of ammonia synthesis are summarized. Finally, some deficiencies in the current research of photo(electro)catalytic ammonia synthesis are highlighted, and the future development trends in this field are analyzed and assessed.