Electrocatalytic Glycerol Upgrading into Glyceric Acid on Ni3Sn Intermetallic Compound

Abstract

Electrochemical glycerol oxidation features an attractive approach of converting bulk chemicals into high-value products such as glyceric acid. Nonetheless, to date, the major product selectivity has mostly been limited as low-value C₁ products such as formate, CO, and CO₂, due to the fast cleavage of carbon-carbon (C-C) bonds during electro-oxidation. Herein, the study develops an atomically ordered Ni₃Sn intermetallic compound catalyst, in which Sn atoms with low carbon-binding and high oxygen-binding capability allow to tune the adsorption of glycerol oxidation intermediates from multi-valent carbon binding to mono-valent carbon binding, as well as enhance ^*OH binding and subsequent nucleophilic attack. The Ni₃Sn electrocatalyst exhibits one of the highest glycerol-to-glyceric acid performances, including a high glycerol conversion rate (1199 µmol h^-1) and glyceric acid selectivity (62 ± 3%), a long electrochemical stability of > 150 h, and the capability of direct conversion of crude glycerol (85% purity) into glyceric acid. The work features the rational design of highly ordered catalytic sites for tailoring intermediate binding and reaction pathways, thereby facilitating the efficient production of high-value chemical products.

Keywords: C–C cleavage; glyceric acid; glycerol oxidation; intermediate adsorption; intermetallic compound.