Metal-Free Single Atom Catalyst for N2 Fixation Driven by Visible Light
Metal-Free Single Atom Catalyst for N2 Fixation Driven by Visible Light
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DOI：
10.1021/jacs.8b07472
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发表时间：
2018-10-31
影响因子：
15
通讯作者：
Wang, Jinlan
中科院分区：
文献类型：
--
作者：
Ling, Chongyi;Niu, Xianghong;Wang, Jinlan
太阳能固定氮（N-2）是氨（NH3）可持续生产最有吸引力的方式，但开发一种高活性、长期稳定和低成本的催化剂仍然是一个巨大的挑战。目前对N-2还原的研究主要集中在电化学方法的金属基催化剂上，而对无金属或太阳能驱动催化剂的研究很少。本文基于电子“接受-给予”的概念，通过广泛的第一性原理计算，提出了一种用于还原N-2的无金属光催化剂，即硼(B)原子，修饰在具有光学活性的石墨碳氮化物（B/g-C3N4）上。结果表明，在B/g-C3N4上，气相N-2可以通过酶促机制高效地还原为NH3，且起始电位低（0.20 V）。此外，b修饰的g-C3N4可以显著增强可见光吸收，使其成为太阳能驱动的N-2还原的理想选择。重要的是，由于其极高的稳定性，进一步证明了设计的催化剂具有很大的合成前景。我们的工作是第一份用于N-2还原的无金属单原子光催化剂的报告，为促进可持续的NH3生产提供了经济有效的机会。
Solar nitrogen (N-2) fixation is the most attractive way for the sustainable production of ammonia (NH3), but the development of a highly active, long-term stable and low-cost catalyst remains a great challenge. Current research efforts for N-2 reduction mainly focus on the metal-based catalysts using the electrochemical approach, while metal-free or solar-driven catalysts have been rarely explored. Herein, on the basis of a concept of electron "acceptance-donation", a metal-free photocatalyst, namely, boron (B) atom, decorated on the optically active graphitic-carbon nitride (B/g-C3N4), for the reduction of N-2 is proposed by using extensive first-principles calculations. Our results reveal that gas phase N-2 can be efficiently reduced into NH3 on B/g-C3N4 through the enzymatic mechanism with a record low onset potential (0.20 V). Moreover, the B-decorated g-C3N4 can significantly enhance the visible light absorption, rendering them ideal for solar-driven reduction of N-2. Importantly, the as-designed catalyst is further demonstrated to hold great promise for synthesis due to its extremely high stability. Our work is the first report of metal-free single atom photocatalyst for N-2 reduction, offering cost-effective opportunities for advancing sustainable NH3 production.