Tafel Analysis Guided Optimization of ZnNP-O-C Catalysts for theSelective 2-Electron Oxygen Reduction Reaction in Neutral Media

The lack of characterizations of the adsorption capability toward intermediates during reactions causes difficulties in determining the structural optimization principle of the catalysts for the 2-electron oxygen reduction reaction (2e(-) ORR). Here, a Tafel-theta method is proposed to evaluate the surface coverage (theta) of important intermediates (*OOH and *OH) on the material surface and further help optimize the catalyst. With the assistance of Tafel-theta analysis, a Zn nanoparticle incorporated oxygen-doped carbon (Zn-NP-O-C) catalyst with high 2e(-) ORR performance (onset of similar to 0.57 V and selectivity of >90.4%) in neutral media was achieved. Both the theoretical calculation and characterization results are consistent with the Tafel-theta deduction, revealing that an appropriate ratio of Zn nanoparticles and bridging O can optimize the *OOH adsorption/desorption strength of the adjacent carbon site. This study not only provides an advanced Zn-NP-O-C catalyst for electrochemical H2O2 production but also proposes a fast and precise method for the comprehensive assessment of future catalysts

Automated summary

By proposing the Tafel-theta method, the surface coverage of important intermediates on catalysts was evaluated, leading to the optimization of catalyst structure and achieving high performance in oxygen reduction reactions.