Electrocatalytic Hydrogenation of Oxygenates using Earth‐Abundant Transition‐Metal Nanoparticles under Mild Conditions

Abstract

Electrocatalytic hydrogenation (ECH) is a sustainable pathway for the synthesis of value-added organic compounds, provided affordable catalysts with high activity, selectivity and durability are developed. Here, we synthesize Cu/C, Ni/C, and CuNi/C nanoparticles and compare their performance to Pt/C, Ru/C, PtRu/C for the ECH of hydroxyacetone, a bio-derived feedstock surrogate containing a carbonyl and a hydroxyl functional group. The non-precious metal electrocatalysts show promising conversion-time behavior, product selectivities, and Faradaic efficiencies. Ni/C forms propylene glycol with a selectivity of 89 % (at 80 % conversion), while Cu/C catalyzes ECH (52 % selectivity) and hydrodeoxygenation (HDO, 48 % selectivity, accounting for evaporation). CuNi/C shows increased turnover frequencies but reduced ECH selectivity (80 % at 80 % conversion) as compared to the Ni/C catalyst. Importantly, stability studies show that the non-precious metal catalysts do not leach at operating conditions.

Upgrading of Bio‐Oil Model Compounds and Bio‐Crude into Biofuel by Electrocatalysis: A Review

“…Electrode commonly consists of catalysts and conductive material (catalyst support), which has a crucial effect on the bio‐oil conversion and products selectivity in bio‐oil ECH process. In detail, electrocatalysts like noble metal, [32b,33,39b,48] base metal, [32a,48a,c,49] alloy, [9a,50] oxide [51] and phosphide [40a] have been reported for upgrading bio‐crude and model compounds by ECH. Besides, graphite, activated carbon and other porous materials as catalyst supports can improve the electrocatalytic performance.…”

Structure Sensitivity in Hydrogenation Reactions on Pt/C in Aqueous‐phase

“…Electrochemical hydrogenation (ECH) conceptually allows low‐temperature hydrogenation with the cathodic potential providing the reduction equivalents ,,,,,. The potential problem with this approach is that the H 2 evolution reaction (HER) competes with ECH .…”

Electrocatalysts for Using Renewably-Sourced, Organic Electrolytes for Redox Flow Batteries

“…Their utility is limited when the supporting electrolyte is aqueous because they are also active for reducing water (to make H 2 ). This limitation can be obviated by using metals with a high overpotential against reducing water while still maintaining the ability to transfer hydrogen [48]. Alternately, it appears that some metals can bind the organic strongly enough to lower the surface concentration of H, such that the H-H combination reaction is suppressed [41].…”