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

Abstract Urea oxidation reaction (UOR) is an ideal replacement of the conventional anodic oxygen evolution reaction (OER) for efficient hydrogen production due to the favorable thermodynamics. However, the UOR activity is severely limited by the high oxidation potential of Ni‐based catalysts to form Ni 3+ , which is considered as the active site for UOR. Herein, by using in situ cryoTEM, cryo‐electron tomography, and in situ Raman, combined with theoretical calculations, a multistep dissolution process of nickel molybdate hydrate is reported, whereby NiMoO 4 ·xH 2 O nanosheets exfoliate from the bulk NiMoO 4 ·H 2 O nanorods due to the dissolution of Mo species and crystalline water, and further dissolution…

• NN
  National Natural Science Foundation of China

  Awards: 22279019, 21875042, 22205038
• SA
  Science and Technology Commission of Shanghai Municipality

  Awards: 21DZ1207102, 21DZ1207103
• NK
  National Key Research and Development Program of China

  Award: 2022YFA1503101