Selective Electrosynthesis of Isolable 4-Hydroxyvalerate from Bio-Based Ketone via Balanced H Chemisorption

Electro-refinery of bio-based levulinic acid (LA) propels a H 2 -free route under ambient conditions for selectively synthesizing 4-hydroxyvalerate (HVA) as a versatile platform molecule. Nevertheless, its performance has long been hampered by the contradictory mechanism relying on active H species (*H) that also induces the severely competing hydrogen evolution reaction (HER). To break this trade-off, we rationalized a balanced *H generation over a screened Pb-Ag catalyst, achieving a jointly improved HVA productivity of 1.43 mmol·h −1 ·cm −2 and 92.1% FE with ∼100% selectivity at –1.38 V RHE, surpassing the Pb-based counterparts. Unlike the typical proton-coupled electron transfer on bare Pb, the activity origin of the Pb-Ag system was attributed to its balanced *H adsorption that could facilitate a greater reaction tendency through the hydrogen atom transfer pathway, engendering the decrease of the hydrogenation barrier without excessively expediting HER, integrated with a synergistic promotion of LA adsorption on a bimetallic interface. Moreover, a three-way separation approach was proposed to synchronously enable the electrolyte recovery and gram-scale synthesis of potassium HVA powder with 90.3% solid yield and 99.5% purity. This work shed light on a balanced *H strategy for producing isolable high-value-added chemicals via biomass upgradation in an electrified process.