A thermo-electroreduction strategy unlocks propylene glycol synthesis from glycerol at ampere level current density.

Chang, Huaiyu; Zhang, Longhai; Mi, Ziyu; Tonanon, Panyawut; Liu, Chengyi; Cao, Xun; Zhang, Mingsheng; Gao, Jiajian et al. · Nat Commun · 2025

basic_science · Level V

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Abstract

The production of valuable chemicals from glycerol can alleviate its large market surplus and reduce emissions that arise from petrochemical-based feedstocks. Here we show that a thermo-electroreduction strategy can expand the scope of glycerol valorization to a product of higher effective H/C ratio, such as propylene glycol. The thermal dehydration of glycerol unlocks the hydroxyacetone intermediate, which can undergo subsequent electrocatalytic hydrogenation to propylene glycol using Co-cluster-decorated Cu foam electrocatalyst. Theoretical simulations suggest that Co/Cu modulates the adsorption configuration of hydroxyacetone, such that all functional groups are in similar distance from the surrounding water layer and the surface. This can facilitate low-energy-barrier hydrogenation of the O atom on hydroxyacetone by solvated H species through an Eley-Rideal-type mechanism, followed by spontaneous hydrogenation of the adjacent C atom. We thus achieve high Faradaic efficiencies towards propylene glycol of ~81% even at current densities up to 1000 mA/cm<sup>2</sup>.