Advanced Materials and Catalysis Group, Institute of Catalysis, Department of Chemistry, Zhejiang University, Hangzhou, 310028, P. R. China.
Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Department of Chemistry, Zhejiang Normal University, Jinhua, 321004, P. R. China.
ChemSusChem. 2022 Aug 5;15(15):e202200532. doi: 10.1002/cssc.202200532. Epub 2022 Jun 22.
Non-polar diatomic molecule activation is of great significance for catalysis. Despite the high atomic efficiency, the catalytic performance of single-atom catalysts is limited by insufficient receiving sites for diatomic molecule adsorption. Here, Fe dimers were successfully synthesized through precisely regulating the metal loading on metal-organic frameworks. The unique role of metal dimers in activating diatomic O molecules was explored. In alkaline electrolytes, the specific oxygen reduction reaction activity of Fe dimers was 7 times higher than that of Fe counterparts. The hydrogen atom transfer probes indicated a different activation mode for O on Fe and Fe dimers, respectively. Theoretical calculation results revealed that Fe dimers opened up a new reaction pathway by promoting the direct breaking of O=O bonds, thus avoiding the usual formation of *OOH intermediates, which helped explain the lower H O yield and higher specific activity.
非极性双原子分子的活化对于催化具有重要意义。尽管原子效率很高，但单原子催化剂的催化性能受到双原子分子吸附接收位点不足的限制。在这里，通过精确调节金属在金属有机骨架上的负载量，成功合成了 Fe 二聚体。探索了金属二聚体在活化双原子 O 分子方面的独特作用。在碱性电解质中，Fe 二聚体的特定氧还原反应活性是 Fe 对应物的 7 倍。氢原子转移探针表明，Fe 和 Fe 二聚体上的 O 分别具有不同的活化模式。理论计算结果表明，Fe 二聚体通过促进 O=O 键的直接断裂开辟了一条新的反应途径，从而避免了通常形成*OOH 中间体，这有助于解释较低的 H2O 产率和更高的比活性。
