Cobalt oxide (Co₃O₄) has attracted considerable interest because of its high catalytic activity, especially for intrinsic catalase (CAT)-mimic and superoxide dismutation (SOD)-mimic activities. However, understanding of its catalytic mechanism from atomic or molecular level remains limited. Here, we propose base-like dissociative, acid-like dissociative and bi-hydrogen peroxide associative mechanisms of CAT-mimic activity, Langmuir–Hinshelwood (LH) and Eley–Rideal (ER) mechanisms of SOD-mimic activity on cobalt oxide surface with atomistic thermodynamic and kinetic details by a combination of rigorous density functional theory and microkinetic modeling. The catalytic activity of Co₃O₄ depends strongly on their size and structure. In this study, Co₃O₄ nanozyme with different size and structure exhibited different catalytic activities in the order of (Co₃O₄)₂ > (Co₃O₄)₃ > Co₃O₄. This order is closely related to their weak, tunable Co–O bonds. Our microkinetic modeling analysis shows that bi-hydrogen peroxide associative mechanisms (mechanism C) of CAT-mimic activity and ER mechanism of SOD-mimic activity for (Co₃O₄)₂ are favorable, which is identified by the rate-determining steps (RDS), Energy span model (ESM), and microkinetic modeling analysis. For the CAT-mimic activities on (Co₃O₄)_n surface, Campbell’s degree of rate control analysis indicates the key to catalyst improvement and design is to stabilize the key steps, which are related to the formation of H₂O molecular. For the SOD-mimic activities of (Co₃O₄)_n, we find the formation of H₂O₂ molecular to be the sole rate-controlling step. Degree of the thermodynamic rate control analysis reveals that the stronger H₂O₂*, OH* binding would facilitate the reaction of CAT-like activities of (Co₃O₄)_n. And the adsorbed OHOO* with large negative degree of thermodynamic rate control would inhibit the reaction of CAT-like activities of (Co₃O₄)_n. Our results have not only provided new insights into deciphering (Co₃O₄)_n artificial enzymes, but will also facilitate the design and construction of other types of target-specific artificial enzymes.

氧化钴（Co ₃ O ₄）由于其高催化活性而引起了极大的兴趣，特别是对于内在过氧化氢酶（CAT）模拟和超氧化物歧化（SOD）模拟活性。但是，从原子或分子水平理解其催化机理仍然有限。在这里，我们提出了类似CAT的模拟活性的类似碱的离解，类似酸的离解和双氢过氧化物的缔合机制，对于氧化钴表面上的SOD模仿活性的Langmuir-Hinshelwood（LH）和Eley-Rideal（ER）机理通过严格的密度泛函理论和微动力学建模相结合，获得原子热力学和动力学细节。Co ₃ O ₄的催化活性很大程度上取决于它们的大小和结构。在这项研究中，具有不同大小和结构的Co ₃ O ₄纳米酶以（Co ₃ O ₄）₂  >（Co ₃ O ₄）₃  > Co ₃ O ₄的顺序表现出不同的催化活性。此顺序与它们的弱且可调的Co-O键密切相关。我们的微动力学模型分析表明，（Co ₃ O ₄）₂的CAT模拟活性的双氢过氧化物缔合机理（机理C）和SOD模拟活性的ER机理通过速率确定步骤（RDS），能量跨度模型（ESM）和微动力学模型分析可以确定这种方法是有利的。对于（Co ₃ O ₄）_n表面上的CAT模拟活性，坎贝尔速率控制分析的程度表明催化剂改进的关键，而设计是稳定与H ₂ O分子形成有关的关键步骤。对于（Co ₃ O ₄）_n的SOD模拟活性，我们发现H ₂ O ₂分子的形成是唯一的速率控制步骤。热力学速率控制分析的程度表明，H ₂ O ₂越强*，OH *的结合将促进（Co ₃ O ₄）_n的CAT类活性的反应。而且，吸附的OHOO *具有较大的负热力学速率控制能力，会抑制（Co ₃ O ₄）_n的类CAT活性反应。我们的结果不仅为破译（Co ₃ O ₄）_n人造酶提供了新的见识，而且还将促进其他类型的目标特异性人造酶的设计和构建。