Sun Kai, Lu Ruihu, Liu Yuge, Webb Joshua, Hanif Muhammad, Zhao Yufei, Wang Ziyun, Waterhouse Geoffrey I N
School of Chemical Sciences, University of Auckland, Auckland, 1010, New Zealand.
State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, China.
Angew Chem Int Ed Engl. 2025 Jan 27;64(5):e202416070. doi: 10.1002/anie.202416070. Epub 2025 Jan 2.
The electrochemical two-electron oxygen reduction reaction (2e ORR) offers a potentially cost-effective and eco-friendly route for the production of hydrogen peroxide (HO). However, the competing 4e ORR that converts oxygen to water limits the selectivity towards hydrogen peroxide. Accordingly, achieving highly selective HO production under low voltage conditions remains challenging. Herein, guided by first-principles density functional theory (DFT) calculations, we show that modulation the first coordination sphere in Co single atom catalysts (Co-N-C catalysts with Co-NO sites), specifically the replacement of Co-N bonds with Co-O bonds, can weaken the *OOH adsorption strength to boost the selectivity towards HO (albeit with a slight decrease in ORR activity). Further, by synthesizing a series of N-doped carbon-supported catalysts with Co-NO active sites, we were able to validate the DFT findings and explore the trade-off between catalytic activity and selectivity for 2e ORR. A catalyst with trans-Co-NO sites exhibited excellent catalytic activity and HO selectivity, affording a HO production rate of 12.86 and an half-cell energy-efficiency of 0.07 during a 100-hours HO production test in a flow-cell.
电化学双电子氧还原反应（2e ORR）为过氧化氢（HO）的生产提供了一条潜在的低成本且环保的途径。然而，将氧气转化为水的竞争性4e ORR限制了对过氧化氢的选择性。因此，在低电压条件下实现高选择性的HO生产仍然具有挑战性。在此，在第一性原理密度泛函理论（DFT）计算的指导下，我们表明调节钴单原子催化剂（具有Co-NO位点的Co-N-C催化剂）中的第一配位层，特别是用Co-O键取代Co-N键，可以减弱*OOH的吸附强度，从而提高对HO的选择性（尽管ORR活性略有下降）。此外，通过合成一系列具有Co-NO活性位点的氮掺杂碳负载催化剂，我们能够验证DFT的发现，并探索2e ORR催化活性和选择性之间的权衡。具有反式Co-NO位点的催化剂表现出优异的催化活性和HO选择性，在流通池中进行的100小时HO生产测试期间，HO产率为12.86 ，半电池能量效率为0.07 。
