Selective Anodic Oxidation of Solketal as Acetal‐Protected Glycerol over Nickel Boride in Alkaline Media to Glyceric Acid**

Abstract

AbstractAlkaline anodic oxidation of glycerol suffers from facile C−C bond cleavage, especially when using non‐precious metal electrocatalysts, which limits the yield of more valuable C3 oxygenates. Usually, a high C3 selectivity is a tradeoff with conversion for most catalysts. Thus, we used solketal as the reactant, which is acetal‐protected glycerol with acetone. CV experiments showed that solketal is oxidized over nickel boride (NixB) at potentials where NiOOH is formed. Electrolysis over NixB in a thin‐film spectroelectrochemical flow cell at 1.58 V vs. RHE to avoid pronounced oxygen evolution showed a stable current density of ca. 6 mA cm−2. Simultaneously recorded ATR‐FTIR spectra revealed solketal conversion to solketalate and formate. Indeed, 59 % conversion and 77 % selectivity to glyceric acid were determined by HPLC after acidic cleavage of the acetal, resulting in a yield of 45 %. Therefore, solketal is a promising reactant for the selective electrosynthesis of glyceric acid.