Replacing oxygen evolution reaction by glycerol electrooxidation on Rh modified Ni(OH)2/C for energy-efficient hydrogen production

Oxygen evolution reaction (OER) is a key reaction for the development of green and sus-tainable energy system based in the production of hydrogen by electrolysis. However, the water splitting required a high overpotential for the oxygen evolution reaction. In this work we investigated the use of the Glycerol Electrooxidation Reaction (GEOR) in alkaline solu-tions on Rh/C, Ni(OH)2/C and Rhx{Ni(OH)2}y/C nanocomposites instead of water as a reagent in the anodic reaction in electrolyzers as a way to reduce the cell overpotential and obtain energy savings. The electrocatalysts were prepared by microwave-assisted alcohol reduc-tion method and characterized by X-ray diffraction. The catalysts presented particles with fcc structure for Rh/C, a hexagonal structure for (Ni(OH)2/C), and (Rh0.3{Ni(OH)2}0.7/C) and (Rh0.5{Ni(OH)2}0.5/C) presented mixed structures with brucite and a a-Ni(OH)2/C structure. The electrochemical performance of Rh0.3{Ni(OH)2}0.7/C presented superior density current at low potential in comparison to the other studied materials. The potential value deter-mined for GEOR at 10 mA cm-2 was nearly 1.29 V vs. RHE in a 0.5 mol L-1 glycerol solution that is 0.3 V less than the value obtain Rh/C in the absence on the organic species. The analysis of the products generated after bulk electrolysis using high-performance liquid chromatography demonstrated that at 1.50 V vs. RHE the main reaction products were and tartronate, glyceraldehyde and oxalate, depending on the employed catalytic material. These results demonstrated that value-added products could be obtained as a promising way to valorize by the glycerol electrooxidation besides the energy saving during the electrolysis for the hydrogen production.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.