Asymmetric Structures to Switch on the Selective Oxygen Reduction to Hydrogen Peroxide

Abstract

The carbon defects coupled with heteroatoms can asymmetrically rearrange local electronic distribution and coordination environment of active sites, improving the catalytic selectivity and activity of two-electron oxygen reduction reaction (2eORR). In this work, an asymmetry defective carbon (asy-DC) structure using wolfberry as the carbon source to adjust the charge distribution of active sites with different degrees of asymmetry by N→S coordination bonds. The asymmetric region significantly exhibits a positive correlation between asymmetry degree and adsorption energy for OOH* (ΔGOOH*), presenting a volcano relation between asymmetry degree and catalytic activity. The optimized asy-DC catalyst exhibits high selectivity and reliable activity after 12 hours of stability testing. This work can provide a new reference into the origin of ORR activity and selectivity.

Keywords: Carbon defect, 2eORR, asymmetry, charge redistribution, catalytic activity