Zhong Xuepeng, Oubla M'hamed, Wang Xiao, Huang Yangyang, Zeng Huiyan, Wang Shaofei, Liu Kun, Zhou Jian, He Lunhua, Zhong Haihong, Alonso-Vante Nicolas, Wang Chin-Wei, Wu Wen-Bin, Lin Hong-Ji, Chen Chien-Te, Hu Zhiwei, Huang Yunhui, Ma Jiwei
Shanghai Key Laboratory for R&D and Application of Metallic Functional Materials, Institute of New Energy for Vehicles, School of Materials Science and Engineering, Tongji University, Shanghai, China.
Max Planck Institute for Chemical Physics of Solids, Dresden, Germany.
Nat Commun. 2021 May 25;12(1):3136. doi: 10.1038/s41467-021-23430-3.
Structural degradation in manganese oxides leads to unstable electrocatalytic activity during long-term cycles. Herein, we overcome this obstacle by using proton exchange on well-defined layered LiMnO with an O3-type structure to construct protonated LiHMnO with a P3-type structure. The protonated catalyst exhibits high oxygen reduction reaction activity and excellent stability compared to previously reported cost-effective Mn-based oxides. Configuration interaction and density functional theory calculations indicate that LiHMnO has fewer unstable O 2p holes with a Mn valence state and a reduced interlayer distance, originating from the replacement of Li by H. The former is responsible for the structural stability, while the latter is responsible for the high transport property favorable for boosting activity. The optimization of both charge states to reduce unstable O 2p holes and crystalline structure to reduce the reaction pathway is an effective strategy for the rational design of electrocatalysts, with a likely extension to a broad variety of layered alkali-containing metal oxides.
锰氧化物的结构降解会导致长期循环过程中电催化活性不稳定。在此，我们通过在具有O3型结构的明确分层LiMnO上进行质子交换来构建具有P3型结构的质子化LiHMnO，从而克服了这一障碍。与先前报道的具有成本效益的锰基氧化物相比，质子化催化剂表现出高氧还原反应活性和优异的稳定性。组态相互作用和密度泛函理论计算表明，LiHMnO具有较少的不稳定O 2p空穴，其Mn价态和层间距离减小，这源于H取代了Li。前者负责结构稳定性，而后者负责有利于提高活性的高传输性能。优化电荷态以减少不稳定的O 2p空穴和晶体结构以缩短反应路径是合理设计电催化剂的有效策略，可能会扩展到各种含碱层状金属氧化物。
