A research team led by Prof. Chen Ping and Associate Prof. Liu Lin from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), in collaboration with Associate Prof. Wu Anan from Xiamen University, discovered that samarium hydride (Sm-H) species, in situ generated on the surface of Ru clusters/Sm2O3 catalyst under reaction conditions, could work synergistically to enhance the catalytic activity of Ru clusters for ammonia synthesis.