Preparation Of Cobalt-Based Catalysts And Its Performance For Glycerol Electrooxidation Coupling With Hydrogen Evolution

Glycerol,a sustainable fuel,is typically produced as a by-product of transesterification of biodiesel,which has the advantages of cheap cost and high functionality.It can be selectively oxidized into fine chemicals with high added value using electrochemical catalytic oxidation,thereby meeting a major strategic demand for sustainable resource development.Moreover,glycerol has a lower anodic oxidation potential（0.69 V（vs.RHE））than the oxygen evolution process（OER）.Combining the hydrogen evolution reaction（HER）with glycerol oxidation reaction（GOR）can significantly boost energy efficiency.The key to attaining widespread application of glycerol oxidation coupling hydrogen evolution is the creation of catalysts with great catalytic activity,excellent selectivity,and long-lasting stability.Focusing on this crucial technical issue,porous cobalt phosphide and sea urchin-like cobalt-copper spinel oxide catalytic materials were made for GOR-coupled HER in an alkaline environment,and their micro-morphology,atomic structure,and element valence were all characterized in accordance with the materials’preparation.In-depth discussion is had regarding how phosphating and atomic phase migration affect the intrinsic activity of catalytic crystal materials.These are the specifics of the work:By using sodium hypophosphite as a source of phosphorus and high-temperature annealing in an inert atmosphere,cobalt phosphide catalyst（Co P/CF）formed on foam copper was effectively created.Linear sweep voltammetry（LSV）testing revealed that the catalyst only needed 1.43 V versus.RHE voltage for its 400 m A cm^-2 industrial current density in a three-electrode system.The catalyst’s stability could last for more than 7 hours as well.The ability to transmit electrons and electrical conductivity are even better in cobalt phosphide.At the same time,the inclusion of phosphorus optimizes the valence state of cobalt metal,which considerably boosts the inherent catalytic activity of the catalyst.The industrialisation of product separation was then researched,and its pairing with conventional methyl formate hydrolysis demonstrated potential futures.By combining cobalt salt and copper salt as raw materials,hydrothermal annealing was effectively used to create the sea urchin-like cobalt copper spinel oxide(Cu_0.7Co_2.3O₄/CF-1,abbreviated as CCO/CF-1)formed on foam copper.CCO/CF-1 has excellent glycerol oxidation performance.It only takes1.17 V_RHE and 1.37 V_RHE voltage to achieve an initial current density of 10 m A cm^-2 and an industrial current density of 400 m A cm^-2.At the same time,the catalyst’s stability can exceed 60 hours,and the assembled dual electrode system requires only 1.85 V to achieve industrial grade current density.The above-mentioned outstanding performance is attributed to the material’s band gap and d-band center being adjusted in the crystal by copper atom migration,which also optimizes its intrinsic catalytic activity and stability.This research demonstrates the crucial impact that atom migration in the crystal has on catalytic activity.It also provides critical context for understanding how structure and performance are related.