南湖新闻网讯（通讯员 丁蕴懿）近日，我校化学学院陈浩教授带领的先进材料与绿色催化团队，在Chemical Engineering Journal发表题为“Enhancing the photoactivation effect on alumina-modified α-iron for highly efficient photothermal catalytic ammonia synthesis”的研究论文。该论文系统探究了光照对固氮催化剂构效关系的影响，为合理设计高效光热催化剂提供了全新见解。

人工将大气中惰性的氮气固定为可被动植物利用的氨，对现代农业发展至关重要。目前最成熟高效的人工固氮方式是 Haber-Bosch 法合成氨，但这种方法需在苛刻条件下反应，会产生大量能耗与碳排放，因此，开发绿色低碳的固氮新技术十分迫切。近年来兴起的光热催化技术，可利用聚焦太阳光通过光热转换驱动反应，显著降低能耗与碳排放。研究表明，光照还可通过光活化效应大幅提升催化效率，展现出比 Haber-Bosch 法更优异的固氮性能。然而，如何合理设计光热催化剂以更好地利用光活化效应，仍是当前亟待探索的前沿课题。

针对这一问题，本研究通过简单沉淀法制备了Al2O3修饰的α-Fe催化剂。结合实验与理论计算研究发现，经 Al2O3修饰后，光热催化固氮效率可提升 4 倍以上，且无需外部加热就能达到1700 μmol g‒1 h‒1的产氨效率。值得注意的是， Al2O3的最佳负载量在光热条件下从热催化时的 10%降至1%，这一变化表明光照改变了催化剂的构效关系。在 400 °C条件下，Fe-1% Al 表现出更为显著的光活化效应，其活性较热催化性能提升 15.3 倍，而 Fe-10% Al 的活性仅提升 7.8 倍。机理研究表明，光诱导产生的热电子转移会选择性促进氮气解离与加氢过程，对氨脱附步骤则无明显影响，进而重构了催化剂的构效关系。该研究提出了有效利用光活化效应的新策略，对高效光热催化剂的开发具有重要意义。

华中农业大学化学学院硕士研究生丁蕴懿、马洪山为论文共同第一作者，化学学院杨懿副教授、汪佩博士、陈浩教授为论文共同通讯作者。该研究得到了国家自然科学基金、中央高校基本科研业务费等项目的资助。

【英文摘要】

Photothermal catalytic ammonia synthesis offers a sustainable approach to address the high energy consumption of the traditional Haber-Bosch process. Although the photoactivation effect significantly enhances catalytic activity, rational catalyst design to maximize this effect still requires further investigation. Herein, Al2O3-modified α-iron catalysts (Fe-x%Al) were synthesized via simple precipitation and systematically investigated through experimental studies and theoretical calculations. Al2O3 modification was demonstrated to significantly enhance the photothermal catalytic ammonia production efficiency by over fourfold, achieving a rate of 1700 μmol g-1 h-1 without the need for external heating. Crucially, the optimal Al2O3 loading decreased from 10% under thermal conditions to 1% under photothermal conditions, suggesting that irradiation alters the catalyst property requirements. At 400°C, Fe-1%Al exhibited a pronounced photoactivation effect, demonstrating a 15.3-fold increase in activity (up to 6746 μmol g-1 h-1) compared to its thermal baseline, whereas Fe-10%Al showed only a 7.8-fold improvement. Mechanistic studies revealed light-induced hot electrons preferentially accelerate N2 dissociation and hydrogenation, thereby reconstructing structure-performance relationships. This study proposes a novel strategy for effectively harnessing the photoactivation effect, providing significant insights into the development of efficient photothermal catalysts.

文章链接：https://www.sciencedirect.com/science/article/pii/S1385894725110243

审核人：陈 浩