Electrocatalytic Glucose Upgrading by Sulfonated Carbon for Sustainable Manufacturing

In a sustainable economy, manufacturing is based on renewable raw materials like biomass instead of nonrenewable ones like petroleum. This work is a step toward that goal: we studied the transformation of glucose into industrial raw materials through electro-oxidation with sulfonated carbon catalyst. Sulfonated carbon has been used as a thermocatalyst for glucose conversion, but until now it has not been used as an electrocatalyst. We identified nine products (oxalic acid, gluconic acid, tartaric acid, maleic acid, glycolic acid, arabinose, formic acid, acetic acid, and 5-hydroxymethylfurfural), whereas glucose electrocatalysis yields that were published by others report five products or less. The optimal conditions in our experiments are a sulfonated carbon catalyst at + 1.5 V versus Ag/AgCl of applied potential and 2 h of oxidation time in 0.5 M K₂CO₃ electrolyte. At that condition, the product yields are 16.3% for formic acid, 5.8% for acetic acid, 4.9% for glycolic acid, 4.6% for 5-hydroxymethylfurfural, 1.6% for oxalic acid, 1.5% for tartaric acid, 1.4% for arabinose, and 1.1% for gluconic acid, for a total of 37.2% for the identified products. The next step is to explore whether sulfonated carbon electro-oxidation can convert cellulose (a polymer of glucose) into those identified products.