Dong Chenlong, Zhang Xilin, Xu Jie, Si Rui, Sheng Jun, Luo Jun, Zhang Shaoning, Dong Wujie, Li Guobao, Wang Weichao, Huang Fuqiang
State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P. R. China.
School of Physics, Henan Normal University, Xinxiang, 453007, P. R. China.
Small. 2020 Feb;16(5):e1905328. doi: 10.1002/smll.201905328. Epub 2020 Jan 10.
Exploring the origin of transition metal (TM) lattice-doped layered double hydroxides (LDHs) toward the oxygen evolution reaction (OER) plays a crucial role in engineering efficient electrocatalysts. Without understanding the physics behind the TM-induced catalytic enhancements, it would be challenging to design the next generation of electrocatalysts. Herein, single Ru atoms are introduced into a CoCr LDHs lattice to improve activity. In 0.1 m KOH, CoCrRu LDHs require only 290 mV overpotential to drive to 10 mA cm and show a Tafel slope of 56.12 mV dec . Electronic structure analyses based on density functional theory confirm that promoted OER activity originates from synergetic charge transfer among Ru, Cr, and Co elements. Specifically, Ru dopants can downshift d states of Co and enhance electron donation of Cr to oxygenates, which essentially breaks the scaling relation and achieves higher activity. This work provides insights into how single atomic Ru dopant tunes the electronic structures of its neighbor's active site Co and thus increases OER activities.
探索过渡金属（TM）晶格掺杂的层状双氢氧化物（LDHs）用于析氧反应（OER）的起源，对于设计高效电催化剂至关重要。如果不了解TM诱导催化增强背后的物理原理，设计下一代电催化剂将具有挑战性。在此，将单个Ru原子引入CoCr LDHs晶格以提高活性。在0.1 m KOH中，CoCrRu LDHs驱动至10 mA cm只需290 mV过电位，且塔菲尔斜率为56.12 mV dec。基于密度泛函理论的电子结构分析证实，OER活性的提高源于Ru、Cr和Co元素之间的协同电荷转移。具体而言，Ru掺杂剂可使Co的d态下移，并增强Cr向含氧化合物的电子给予，这从本质上打破了标度关系并实现了更高的活性。这项工作为单个原子Ru掺杂剂如何调节其相邻活性位点Co的电子结构从而提高OER活性提供了见解。
