Boosting the Electrolysis of Monosaccharide-Based Streams in an Anion-Exchange Membrane Cell

Abstract

A systematic study on the electrochemical reforming of monosaccharides (fructose, glucose, and xylose) using Ptbased anodic electrocatalysts is here presented for the first time to completely optimize the anodic catalyst and electrolyzer operating conditions. First, the electro-oxidation of each molecule was studied using a monometallic (Pt) and two bimetallic (PtNi and PtCo) anodic electrocatalysts supported on graphene nanoplatelets (GNPs). Tests in a three-electrode cell showed superior electrochemical activity and durability of PtNi/GNPs, especially at potentials higher than 1.2 V vs RHE, with the highest electrocatalytic activity in D-xylose electro-oxidation. Then, monometallic (Pt and Ni) and bimetallic electrocatalysts with different Pt:Ni mass ratios (1:1 and 2:1) were studied for D-xylose electro-oxidation, with the 2:1 mass ratio presenting the best results. This electrocatalyst was selected as the most suitable for scaleup to an anion-exchange membrane electrolyzer, where the optimal operating potential was determined. Additionally, stable operating conditions of the electrolyzer were achieved by cyclic H 2 production and cathodic regeneration polarization steps. This led to suitable and reproducible H 2 production rates throughout the production cycles for renewable hydrogen production from biomass-derived streams.