3D graphene-mixed metal oxide-supported carbon[sbnd]palladium quantum dot nanoarchitectures – A facile bifunctional electrocatalyst for direct ethylene glycol fuel cells and oxygen evolution reactions

Nanoarchitectured carbon-palladium quantum dot (C-Pd)-supported manganese-titanium oxide/3D graphene (MTOx-3DG) catalyst is developed using a two-step process, for ethylene glycol fuel cells and oxygen evolution reactions. About 10 nm–sized carbon shell and a 5 nm-sized Pd catalyst over an MTOx-3DG support is established by the facile green chemical approach. The C-Pd-MTOx-3DG nanoarchitectured catalyst possesses excellent electrocatalytic activity with the peak current density of 23.8 mA/cm² for ethylene glycol electrooxidation. In addition, MTOx-3DG support material helps to remove the poisonous intermediates formed during the ethylene glycol electrooxidation. We addressed this point by suitable method in which about 80% of the poisonous compounds are removed, with the help of a supporting material at higher forward potential regions. In addition to that the formation of Pd adatoms and synergism of mixed metal atoms helped to effectively oxidize the fuel. The physical and chemical analyses show that the prepared C-Pd-MTOx-3DG electrocatalyst is nanostructured, with excellent catalytic activity, better intermediate tolerance, and sound long-term stability of the catalyst, attributed to the uniform dispersion of the Pd QDs and excellent interaction between the noble metal catalyst and the support. The present study sketches a simple and novel electrocatalyst for direct ethylene glycol fuel cells.