Wang Ming Hua, Lou Zhen Xin, Wu Xuefeng, Liu Yuanwei, Zhao Jia Yue, Sun Kai Zhi, Li Wen Xin, Chen Jiacheng, Yuan Hai Yang, Zhu Minghui, Dai Sheng, Liu Peng Fei, Yang Hua Gui
Key Laboratory for Ultrafine Materials of Ministry of Education, Shanghai Engineering Research Center of Hierarchical Nanomaterials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai, 200237, P. R. China.
Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, Key Laboratory of Materials-Oriented Chemical Engineering of Xinjiang Uygur Autonomous Region, Engineering Research Center of Materials-Oriented Chemical Engineering of Xinjiang Bingtuan, School of Chemistry and Chemical Engineering, Shihezi University, Xinjiang, 832003, P. R. China.
Small. 2022 May;18(19):e2200303. doi: 10.1002/smll.202200303. Epub 2022 Apr 7.
High-valence metal-doped multimetal (oxy)hydroxides outperform noble metal electrocatalysts for the oxygen evolution reaction (OER) owing to the modified energetics between 3d metals and high-valence dopants. However, the rational design of sufficient and subtle modulators is still challenging. With a multimetal layered double hydroxide (LDH) as the OER catalyst, this study introduces a series of operando high-valence dopants (Cr, Ru, Ce, and V), which can restrict the 3+ valence states in the LDH template to prevent phase separation and operando transfer to the >3+ valence states for sufficient electronic interaction during the OER process. Through density functional theory simulations, ultrathin Cr-doped NiFe (NiFeCr) LDH is synthesized with strong electronic interaction between Cr dopants and NiFe bimetallic sites, evidenced by X-ray absorption spectroscopy. The resulting NiFeCr-LDH catalyzes the OER with ultralow overpotentials of 189 and 284 mV, obtaining current densities of 10 and 1000 mA cm , respectively. Further, a NiFeCr-LDH anode is coupled in the anion exchange membrane electrolyzers to promote alkaline water splitting and CO -to-CO electrolysis, which achieves low full cell voltages at high current densities.
由于3d金属与高价掺杂剂之间的能量学发生了改变，高价金属掺杂的多金属（氧）氢氧化物在析氧反应（OER）中比贵金属电催化剂表现更优。然而，合理设计充足且微妙的调节剂仍然具有挑战性。本研究以多金属层状双氢氧化物（LDH）作为OER催化剂，引入了一系列原位高价掺杂剂（Cr、Ru、Ce和V），这些掺杂剂可以限制LDH模板中的3 + 价态，防止相分离，并在OER过程中原位转移到>3 + 价态以实现充分的电子相互作用。通过密度泛函理论模拟，合成了超薄Cr掺杂的NiFe（NiFeCr）LDH，Cr掺杂剂与NiFe双金属位点之间具有强烈的电子相互作用，这由X射线吸收光谱证实。所得的NiFeCr-LDH催化OER时的过电位分别低至189和284 mV，对应的电流密度分别为10和1000 mA cm²。此外，将NiFeCr-LDH阳极与阴离子交换膜电解槽耦合，以促进碱性水分解和CO₂到CO的电解，在高电流密度下实现了较低的全电池电压。
