Multistep Dissolution of Lamellar Crystals Generates Superthin Amorphous Ni(OH)2 Catalyst for UOR

• DOI: 10.1002/adma.202301549
• Publication Date: 2023-04-14T16:29:19Z
• Authors: Yajie Zhu; Cheng Liu; Shiwen Cui; Zhuorong Lu; Jinyu Ye; Yunzhou Wen; Wenjuan Shi; Xiaoxiong Huang; Liangyao Xue; Juanjuan Bian; Youyong Li; Yifei Xu; Bo Zhang
• Keywords: 02 engineering and technology; 0210 nano-technology

Urea oxidation reaction (UOR) is an ideal replacement of the conventional anodic oxygen evolution (OER) for efficient hydrogen production due to favorable thermodynamics. However, UOR activity severely limited by high potential Ni-based catalysts form Ni3+ , which considered as active site UOR. Herein, using in situ cryoTEM, cryo-electron tomography, and Raman, combined with theoretical calculations, a multistep dissolution process nickel molybdate hydrate reported, whereby NiMoO4 ·xH2 O nanosheets exfoliate from bulk ·H2 nanorods Mo species crystalline water, further results superthin amorphous (II) hydroxide (ANH) flocculus catalyst. Owing structure, ANH catalyst can be oxidized NiOOH at much lower than Ni(OH)2 finally exhibits more order magnitude higher current density (640 mA cm-2 ), 30 times mass activity, 27 TOF those The mechanism provides effective methodology preparation highly catalysts.