Enhancing Glycerol Conversion and Selectivity toward Glycolic Acid via Precise Nanostructuring of Electrocatalysts
Dohee Kim, Lee Seul Oh, Ying Chuan Tan, Hakhyeon Song, Hyung Ju Kim, Jihun Oh
Abstract
The glycerol electro-oxidation reaction (GEOR) can economically convert glycerol, a byproduct of biodiesel production, to glycolic acid. Herein, nanostructured Au catalysts were fabricated on a Si substrate by the electrochemical reduction of anodic-treated (RA-treatment) Au films, which tuned the surface area from 1 to 16 cm2. Treatment of 0.1 M glycerol at 1.0 V (vs RHE) for 2 h in 1 M KOH solution afforded a glycerol conversion and glycolic acid selectivity of 50.9 and 47%, respectively. The RA-Au catalyst selectively afforded glycolic acid from glycerol due to the enhanced facet-dependent OH adsorption, especially at the (100) and (110) sites, as well as the increased surface area. RA treatment of a Au-coated Ni foam further enhanced the GEOR performance, affording 68.7% glycerol conversion and 41.2% glycolic acid selectivity at 1.0 V (vs RHE) within 2 h by providing more active sites.