Mehta Shivangi, Elmerhi Nada, Kaur Sukhjot, Mohammed Abdul Khayum, Nagaiah Tharamani C, Shetty Dinesh
Department of Chemistry, Indian Institute of Technology Ropar, Rupnagar, Punjab, 140001, India.
Department of Chemistry, Khalifa University of Science & Technology, Abu Dhabi, P.O. Box 127788, UAE.
Angew Chem Int Ed Engl. 2025 Jan 27;64(5):e202417403. doi: 10.1002/anie.202417403. Epub 2024 Nov 22.
Tuning the charge density at the active site to balance the adsorption ability and reactivity of oxygen is extremely significant for driving a two-electron oxygen reduction reaction (ORR) to produce hydrogen peroxide (HO). Herein, we have highlighted the influence of intermolecular polarity in covalent organic frameworks (COFs) on the efficiency and selectivity of electrochemical HO production. Different C3 symmetric building blocks have been utilized to regulate the charge density at the active sites. The benzene-cored COF, which exhibits reduced polarity than the triazine-cored COF, displayed enhanced performance in HO production, achieving 93.1 % selectivity for HO at 0.4 V with almost two-electron transfer and a faradaic efficiency of 90.5 %. In-situ electrochemical Raman spectroscopy and scanning electrochemical microscopy (SECM) were employed to confirm HO generation and analyze spatial reactivity patterns. These techniques provided detailed insights into localized catalytic behavior, emphasizing the influence of core polarity.
调节活性位点处的电荷密度以平衡氧的吸附能力和反应性对于驱动两电子氧还原反应（ORR）以产生过氧化氢（HO）极为重要。在此，我们强调了共价有机框架（COF）中分子间极性对电化学产生HO的效率和选择性的影响。已使用不同的C3对称构建块来调节活性位点处的电荷密度。与三嗪核COF相比极性降低的苯核COF在HO产生方面表现出增强的性能，在0.4 V时对HO的选择性达到93.1%，几乎具有两电子转移，法拉第效率为90.5%。采用原位电化学拉曼光谱和扫描电化学显微镜（SECM）来确认HO的产生并分析空间反应模式。这些技术提供了对局部催化行为的详细见解，强调了核心极性的影响。
