Manganese Oxides (Mn3O4 & α‐MnO2) as Co‐catalysts in Pd‐Based Nanomaterials for the Ethylene Glycol Electro‐Oxidation.

Abstract Incorporation of α‐MnO 2 and Mn 3 O 4 during the synthesis of Pd nanoparticles promoted better particle anchoring. Especially the Mn single spinel (Mn 3 O 4 ) decreased the Pd particle size from ∼10 nm (obtained for Pd/C and Pd/α‐MnO 2 ) to 4.4 nm. HR‐TEM and XPS analysis confirmed electronic changes from a better interaction between Pd and Mn 3 O 4 , decreasing the energy barriers for alcohol oxidation, obtaining the lowest apparent activation energy (15.54 kJ mol −1 ) and resistance to charge transfer (1.44 Ω cm 2 ). The Pd/Mn 3 O 4 /C electrocatalyst displayed a current density of 334.74 mA cm −2 at 2 M EG+2 M KOH with an onset potential of −0.32 V vs . NHE. This current density was 2.2 and 3.6‐fold higher than that obtained using Pd/C and Pd/α‐MnO 2 /C. Further tests using sorbitol and glycerol as fuels revealed that maximum current densities of 255.2 and 472.9 mA cm −2 can be achieved.