The formation of surface Li-Fe ternary hydride and its function on catalytic ammonia synthesis at low temperatures, Peikun Wang, Hua Xie, Jianping Guo, Zhi Zhao, Xiangtao Kong, Wenbo Gao, Fei Chang, Teng He, Guotao Wu, Mingshu Chen, Ling Jiang, Ping Chen, Angew. Chem. Int. Ed., 2017, 56, 8716-8720.