A Computation-Guided Design of Highly Defined and Dense Bimetallic Active Sites on a Two-Dimensional Conductive Metal-Organic Framework for Efficient H 2 O 2 Electrosynthesis

• Published in: Angewandte Chemie International Edition 2024-11, Vol.63 (46), p.e202408500
• Main Authors: Li, Zhenxin, Jia, Jingjing, Sang, Zhiyuan, Liu, Wei, Nie, Jiahuan, Yin, Lichang, Hou, Feng, Liu, Jiachen, Liang, Ji
• Format: Article
• Language: English
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202408500

Electrochemical synthesis of hydrogen peroxide (H O ) via the two-electron oxygen reduction reaction (2e -ORR) provides an alternative method to the energy-intensive anthraquinone method. Metal macrocycles with precise coordination are widely used for 2e -ORR electrocatalysis, but they have to be commonly loaded on conductive substrates, thus exposing a large number of 2e -ORR-inactive sites that result in poor H O production rate and efficiency. Herein, guided by first-principle predictions, a substrate-free and two-dimensional conductive metal-organic framework (Ni-TCPP(Co)), composed of CoN sites in porphine(Co) centers and Ni O nodes, is designed as a multi-site catalyst for H O electrosynthesis. The approperiate distance between the CoN and Ni O sites in Ni-TCPP(Co) weakens the electron transfer between them, thus ensuring their inherent activities and creating high-density active sites. Meanwhile, the intrinsic electronic conductivity and porosity of Ni-TCPP(Co) further facilitate rapid reaction kinetics. Therefore, outstanding 2e -ORR electrocatalytic performance has been achieved in both alkaline and neutral electrolytes (>90 %/85 % H O selectivity within 0-0.8 V vs. RHE and >18.2/18.0 mol g  h H O yield under alkaline/neutral conditions), with confirmed feasibility for water purification and disinfection applications. This strategy thus provides a new avenue for designing catalysts with precise coordination and high-density active sites, promoting high-efficiency electrosynthesis of H O and beyond.