Electroreduction of CO₂ into hydrocarbons could contribute to alleviating energy crisis and global warming. However, conventional electrocatalysts usually suffer from low energetic efficiency and poor durability. Herein, atomic layers for transition‐metal oxides are proposed to address these problems through offering an ultralarge fraction of active sites, high electronic conductivity, and superior structural stability. As a prototype, 1.72 and 3.51 nm thick Co₃O₄ layers were synthesized through a fast‐heating strategy. The atomic thickness endowed Co₃O₄ with abundant active sites, ensuring a large CO₂ adsorption amount. The increased and more dispersed charge density near Fermi level allowed for enhanced electronic conductivity. The 1.72 nm thick Co₃O₄ layers showed over 1.5 and 20 times higher electrocatalytic activity than 3.51 nm thick Co₃O₄ layers and bulk counterpart, respectively. Also, 1.72 nm thick Co₃O₄ layers showed formate Faradaic efficiency of over 60 % in 20 h.

中文翻译：

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超薄的Co3O4层实现了优化的CO2电解还原甲酸酯

将CO ₂电还原为碳氢化合物可有助于缓解能源危机和全球变暖。然而，常规的电催化剂通常遭受低的能量效率和差的耐久性。在此，提出了用于过渡金属氧化物的原子层，以通过提供超大比例的活性位，高电子电导率和优异的结构稳定性来解决这些问题。作为原型，通过快速加热策略合成了1.72和3.51 nm厚的Co ₃ O ₄层。原子厚度使Co ₃ O ₄具有丰富的活性位点，从而确保了较大的CO ₂吸附量。费米能级附近电荷密度的增加和分散使得电子电导率提高。1.72 nm厚的Co ₃ O ₄层分别显示出比3.51 nm厚的Co ₃ O ₄层和本体对应物高1.5倍和20倍的电催化活性。同样，厚度为1.72 nm的Co ₃ O ₄层在20小时内显示出甲酸法拉第效率超过60％。