Recent Progress in Alloy-Based Catalysts for the Electrocatalytic Hydrogenation of Biomass-Derived Molecules

Abstract

Biomass is an abundant renewable carbon resource for the sustainable production of fuels and value-added chemicals. Electrocatalytic hydrogenation (ECH) provides a mild and attractive route for upgrading biomass-derived molecules without the need for externally supplied high-pressure H₂. However, the structural complexity and multifunctionality of biomass substrates give rise to intricate reaction networks, while the competing hydrogen evolution reaction (HER) often limits Faradaic efficiency and product selectivity. In recent years, alloy-based catalysts have attracted increasing attention because of their outstanding hydrogenation performance in biomass electrocatalysis. This review summarizes recent progress in alloy-based catalysts for the ECH of biomass-derived molecules, covering phenolic compounds, aldehydes, and lignin-related substrates. Emphasis is placed on mechanistic understanding, including Langmuir–Hinshelwood and proton-coupled electron transfer pathways, as well as on structure–activity/selectivity relationships. Key challenges and future opportunities are also discussed from the perspectives of mechanism-guided catalyst design, electrolyte and reactor engineering, and the upgrading of complex biomass feedstocks.