Electrocatalytic Oxidation of Glycerol to Value-Added Compounds on Pd Nanocrystals

Pd octahedral, rhombicdodecahedral, and cubic nanoparticles (Pd-OCTA, Pd-RD, and Pd-CUBE NPs) were synthesized,characterized, and studied as catalysts for the glycerol electrooxidationreaction (GEOR) in a strongly alkaline medium at 20 and 60 & DEG;C.The highest mass activity of 0.050 and 0.183 mA/& mu;g(Pd) was observed on Pd-OCTA at 20 and 60 & DEG;C, respectively,whereas Pd-CUBE exhibited the highest specific activityof 1.49 and 12.84 mA/cm(Pd) (2), respectively. TheGEOR products were analyzed by high-performance liquid chromatography(HPLC), and their selectivity and overall glycerol conversion wereevaluated at 0.86 V vs RHE. The selectivity toward the three-carbonchain (C3) GEOR products was similar for the different types of catalysts,with Pd-OCTA and Pd-CUBE NPs achieving more than50% selectivity at 20 & DEG;C and more than 60% at 60 & DEG;C. Glyceratewas the overall dominant product for all catalysts, with a selectivityof up to 42%. The glycerol conversion was found to be highest forPd(OCTA)21% at 20 & DEG;C and 82% at 60 & DEG;C,while Pd-RD was the least active and showed less than 3%conversion at 20 & DEG;C and 35% at 60 & DEG;C. Based on the GEORproduct distribution, a reaction mechanism was proposed.

Automated summary

Pd octahedral, rhombicdodecahedral, and cubic nanoparticles were synthesized and studied as catalysts for glycerol electrooxidation reaction (GEOR) in a strongly alkaline medium. Different types of catalysts exhibited varying levels of mass activity and specific activity. Glycerate was the dominant product with high selectivity, and a proposed reaction mechanism was based on the product distribution.