Accelerated Selective Electrooxidation of Ethylene Glycol and Inhibition of C–C Dissociation Facilitated by Surficial Oxidation on Hollowed PtAg Nanostructures via In Situ Dynamic Evolution

Abstract

Electro-upgrading of low-cost alcohols such as ethylene glycol is a promising and sustainable approach for the production of value-added chemicals while substituting energy-consuming OER in water splitting. However, the sluggish kinetics and possibility of C–C dissociation make the design of selective and efficient electrocatalysts challenging. Herein, we demonstrate the synthesis of a hollowed bimetallic PtAg nanostructure through an in situ dynamic evolution method that could efficiently drive the selective electrochemical ethylene glycol oxidation reaction (EGOR). The resulting mild surficial oxidation has intrinsically improved EGOR activity, exhibiting a remarkable performance toward glycolate (selectivity up to 99.2% and faradic efficiency ∼97%) at high current density with low overpotential (355 mA·cm^–2 at 1.0 V, 16.3 A·mg_Pt^–1), exceeding prior outcomes. Through comprehensive operando characterization and theoretical calculations, this study systematically reveals that the in situ formation of Pt–O(H)_ad is pivotal for modulating the electronic structure of surface and facilitating the selective electrooxidation and adsorption of −CH₂OH. The competitive C–C dissociation pathway toward HCOO^– is concurrently inhibited in comparison to Pt. An industrial-level current coupled with hydrogen production at low cell voltages was also achieved. These findings offer more in-depth mechanistic understanding of the EGOR’s reaction pathway mediated by surface environment in Pt-based electrocatalysts.