Linear paired electrochemical valorization of glycerol enabled by the electro-Fenton process using a stable NiSe2 cathode

Electrochemical valorization of surplus biomass-derived feedstocks, such as glycerol, into high-value chemicals offers a sustainable route for utilization of biomass resources and decarbonization of chemical manufacturing; however, glycerol is typically valorized solely via anodic oxidation, with lower-value products such as hydrogen gas generated at the cathode. Here, we establish the efficient cathodic valorization of glycerol to the desirable C3 oxidation products via the electro-Fenton process at a stable NiSe2 cathode, built upon the theoretical understanding and experimental demonstration of the high selectivity and stability of NiSe2 toward acidic H2O2 electrosynthesis. A proof-of-concept linear paired electrochemical process for concurrent valorization of glycerol into the same oxidation products at both NiSe2 cathode and Pt anode achieves high selectivity for value-added C3 products and high glycerol conversion with little external energy input needed, when the electro-Fenton generation of hydroxyl radicals is carefully controlled. This conceptual strategy of linear pairing is generalizable for enabling atom-efficient electro-refinery of diverse biomass-derived feedstocks.