CO‐Tolerant Ethylene Glycol Oxidation on p–d Hybridized Platinum Ditelluride for Seawater Artificial Leaves

Abstract

ABSTRACT Seawater‐based artificial leaves are fundamentally constrained by anodic surface poisoning and insufficient photovoltage for bias‐free reaction under complex electrolytes. Here we report a pH‐gradient photoelectrochemical–electrochemical (PEC–EC) system that couples photoelectrochemical hydrogen evolution reaction (HER) and electrochemical ethylene glycol oxidation reaction (EGOR) enabled by CO‐tolerant 1T‐PtTe 2 in both fresh water and natural seawater. As an anodic electrocatalyst for EGOR, platinum ditelluride exhibits a low onset potential of 0.42 V vs. RHE, achieves highly selective production of the value‐added product glycolate (GA) with a Faradaic efficiency of 96.4% at 0.9 V vs. RHE, and maintains high stability in natural seawater. Electronic structure analysis reveals that tellurium incorporation induces a downshift of the platinum d band center, weakening the adsorption of CO‐derived intermediates and suppressing surface poisoning without compromising reactant activation. Our PEC–EC device delivers bias‐free current densities of 37.85 mA cm −2 in fresh water and 37.18 mA cm −2 in natural seawater and sustains continuous hydrogen and glycolate production for 120 h. The demonstration of this PEC–EC system provides a general framework for designing bias‐free photoelectrochemical devices operating at appreciable current densities and advances the practical implementation of seawater‐based artificial leaves.