In-situ generation of enhanced Pd-Co nanoparticles using various stabilizing agents decorated on reduced graphene oxide as electrocatalyst for oxygen reduction reaction

Abstract

The synthesis and characterization of PdCo nanoparticles deposited on reduced graphene oxide as an electrocatalyst for the oxygen reduction reaction have been successfully carried out. This research aims to investigate the influence of various stabilizing agents on the character of the metal nanoparticles towards the activity of the oxygen reduction reaction (ORR). Reduced graphene oxide (RGO) acts as a supporting material for the PdCo nanoparticles. This material was produced from graphite as a raw material that was oxidized using the Tour method. The PdCo/RGO material was synthesized by in-situ generation with the various stabilizing agent types of cetyltrimethylammonium bromide (CTAB), hexamethylenetetramine (HMTA) and a combination of CTAB-HMTA. The results showed that the optimal stabilizing agent type for PdCo/RGO is HMTA (PdCo-H/RGO), giving PdCo nanoparticles with the smallest size, the most uniform shape and the most dispersion on the RGO surface. The ORR catalytic test showed that PdCo-H/RGO displayed activity, with the number of electron transfers being 3.64, which follows the direct 4-electron reduction pathway of the ORR. The catalyst stability test showed that PdCo-H/RGO had relatively high durability with an E1/2 negative shift of 57.6 mV.