Enhanced Activity Promoted by CeOx on a CoOx Electrocatalyst for the Oxygen Evolution Reaction

초록

Included among the many challenges regarding renewable energy technology are improved electrocatalysts for the oxygen evolution reaction (OER). In this study, we report a novel bifunctional electrocatalyst based on a highly dense CoOx catalyst by introducing CeOx The CoOx catalyst is fabricated by two-step electrodeposition, including Co seed formation, to obtain a very dense, layered structure, and CeOx is also successfully deposited on the CoOx catalyst. CoOx is an active catalyst showing good activity (eta = 0.331 V at 10 mA cm(-2)) and also stability for the OER. Higher activity is observed with the CeOx/CoOx electrocatalyst (eta = 0.313 V at 10 mA cm(-2)). From mechanistic studies conducted with synchrotron-based photoemission electron spectroscopy and DFT calculations, Ce promotes a synergistic effect by perturbing the electronic structure of surface Co species (facile formation to CoOOH) on the CoOx catalyst and optimizes the binding energy of intermediate oxygenated adsorbates.

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