Elucidating the Influence of Catalyst Cycling and Activation on the Activity of Ni‐based Layered Double Hydroxides for Electrochemical Oxidation of Ethylene Glycol to Formate

Ni-based layered double hydroxides (LDH) are tested in electrochemical ethylene glycol oxidation and investigated regarding their activity. NiMn and NiCo LDH show promising electrolysis results especially in combination with electrode conditioning and activation, increasing formate yields by up to 68% at high Faraday efficiencies.

The efficient production of green hydrogen is a crucial step toward the development of economically effective ecological alternatives to fossil fuels. However, current water electrolysis still struggles with the high overpotential of the oxygen evolution reaction (OER). Replacing OER with electrochemical ethylene glycol oxidation (EGOR) would not only decrease the needed reaction potential for anode oxidation but also make use of the large amounts of polyethylene terephthalate (PET) waste produced every day. Ni-based layered double hydroxides (LDH) have previously found increased attention for their cost effectiveness, stability, and high catalytic activity in OER. This work discusses the applicability of Ni-based LDH materials in EGOR and investigates their catalytic ability in electrolysis, taking commonly used activation methods like cyclic voltammetry conditioning and chronoamperometric activation into account. The results confirm highly selective oxidation towards formate with yields of up to 30.7% for NiMn LDH and NiCo LDH at 1.4 V versus RHE, reaching Faraday efficiencies and carbon balances >90%.

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