Hydrogen peroxide (H 2 O 2 ) is a vital green oxidant with broad applications ranging from disinfection to chemical manufacturing. However, its industrial production remains heavily reliant on the energy-intensive and waste-generating anthraquinone process. The electrochemical two-electron oxygen reduction (2e − ORR) offers a sustainable alternative, enabling on-site H 2 O 2 generation powered by renewable electricity. While acidic conditions align better with application scenarios, developing efficient and stable non-precious metal catalysts for acidic 2e − ORR has proven to be challenging.
Recently, the research team led by Prof. Jianfeng Jia from Shanxi Normal University has unveiled a breakthrough in electrochemical H 2 O 2 synthesis. The study, published in Science Bulletin , reports a novel catalyst, Cr–N 4 /C(O), which composed of isolated Cr atoms anchored on a N-doped carbon matrix and further modified with O-functional groups.
The research journey began with molecular dynamics simulations, which uncovered a unique "self-adjusting" mechanism. Contrary to the long-held belief that CrN 4 structures bind oxygen too strongly for effective catalysis, the team found that the pyrolyzed Cr–N 4 site spontaneously coordinates with an axial oxygen atom during the reaction. This self-formed structure fine-tunes the site's electronic properties, effectively preventing it from oxygen poisoning and enabling the reaction to towards H 2 O 2 .
Guided by this theoretical insight, the team synthesized the catalyst using a confinement strategy to ensure atomic dispersion of Cr. A subsequent mild thermal treatment in air introduced oxygen functional groups onto the carbon substrate. This peripheral engineering was crucial, creating an electron-deficient Cr center. The synergistic effect between the axial and peripheral O atoms optimized the interaction with O 2 molecules, stabilizing the O–O bond and steering the reaction selectively toward H 2 O 2 formation. The Cr–N 4 /C(O) catalyst demonstrates highly efficient, selective, and stable H 2 O 2 electrosynthesis in acidic media. It outperforms conventional Co-based catalysts by effectively suppressing H 2 O 2 reduction, retarding its decomposition, and exhibiting enhanced metal-leaching resistance.
This research not only identifies a compelling new catalyst candidate for acidic 2e − ORR catalysis but also offers a novel perspective on designing catalysts with self-adaptive features.
Science Bulletin
Experimental study