Experimental and DFT investigation of 3D-HBGP/Pt/Co as a superb electrocatalyst for methanol oxidation reaction

Three-dimensional hollow balls of graphene oxide and polyaniline (3D-HBGP) nanocomposite were constructed by the self-assembly of graphene oxide (GO) and the polymerization of polyaniline (PANI) on poly(methyl methacrylate) (PMMA) particles. The 3D-HBGP was utilized as the support catalyst for platinum-cobalt (Pt-Co) that was electrochemically deposited on its surface for methanol oxidation reaction. Electrochemical measurements illustrates that the peak current density of 3D-HBGP/Pt/Co is 22.53 mA/cm(2), which is 2.48 higher than Pt-Co alloy without 3D-HBGP support. According to this observation, the electro-catalytic activity of 3D-HBGP/Pt/Co is higher than that of Pt-Co electrocatalyst for methanol oxidation reaction (MOR). Compared to Pt-Co electrocatalyst, the electrochemical active surface area (ECSA) of 3D-HBGP/Pt/Co increases to 20.38 m(2)/g during cyclic voltammetry (CV) test. In addition, multi-scan cyclic voltammetry indicates that the 3D-HBGP/Pt/Co electrocatalyst has great catalytic stability for MOR. The density functional theory (DFT) calculation results reveal that utilizing the 3D-HBGP structure alongside Pt and Co leads to decreasing of the energy gap and increasing of the reactivity of catalyst which is in good agreement with experimental findings. The current study results (performance and stability) illustrate that the fabricated 3D-HBGP/Pt/Co electrocatalyst can be a prospective anode catalyst for direct methanol fuel cell (DMFC). (C) 2018 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.