Prof. Lele Duan’s group at the Center of Artificial Photosynthesis for Solar Fuels, Westlake University, recently published a research article in Nature Communications entitled “Steering acidic oxygen reduction selectivity of single-atom catalysts through the second sphere effect.”
Taking inspiration from nature’s metalloenzymes, the team developed a new design strategy for enzyme-mimetic single-atom catalysts (SACs) by engineering an enzyme-like second-sphere microenvironment around atomically dispersed active site. Unlike conventional SACs that mainly tune the first coordination sphere (e.g., the metal–N₄ structure), this work introduces a flexible functional group that creates a three-dimensional “reaction pocket” capable of forming hydrogen-bonding interactions and facilitating proton transfer during oxygen reduction. This biomimetic second-sphere regulation dramatically shifts the oxygen reduction pathway toward the two-electron route in acidic electrolyte, enabling highly selective H₂O₂ generation. As a result, the catalyst boosts H₂O₂ selectivity from ~28% to as high as 97% in acidic media. The team further validated its practical promise in a membrane electrode assembly (MEA), achieving continuous production of 1.0 M H₂O₂ for over 100 hours, providing a robust platform for selective electrochemical synthesis guided by enzyme-inspired principles.
Visiting student Siyan Shu, a master’s candidate, is a co-first author of this paper. Prof. Lele Duan (Center of Artificial Photosynthesis for Solar Fuels, Westlake University) is the corresponding author.