Effect of Co‐Ni Ratio in Graphene Based Bimetallic Electro‐catalyst for Methanol Oxidation

Abstract

In this paper the electro‐catalytic oxidation of methanol is studied on the non‐noble catalysts Ni–Co/graphene. The bimetallic electro‐catalyst was prepared with different Co–Ni ratios by using simple solution synthesis method. The synthesized materials were characterized by X‐ray diffraction (XRD) and scanning electron microscopy (SEM) for their structure and morphological changes. The electro‐catalytic activity of Ni–Co/graphene for methanol oxidation was investigated by cyclic voltammetry (CV) on glass carbon electrode (GCE) in alkaline medium with 1M methanol solution. The results of various electro‐catalysts have shown significant electro‐oxidation towards methanol. Increasing the Ni concentration in catalyst has promoted the oxidation reaction at the Co–Ni/graphene catalyst. This study reveals that the low‐cost electro‐catalyst Ni–Co/graphene has great potential for DMFC applications.

Nanocomposites of NiO/CuO Based MOF with rGO: An Efficient and Robust Electrocatalyst for Methanol Oxidation Reaction in DMFC

“…Over potential is calculated by using the formula (E-E o ) [58]. Among all the composites (i.e., 1-5 wt% and 8 wt% rGO-NiO/CuO MOF and NiO/CuO MOF), 5 wt% rGO-NiO/CuO MOF shows the lowest over potential value; this suggests that the inclusion of rGO may not only increase the catalyst surface area but it may also make the accessibility of reactant toward electrode easier and consequently, it apprehends more ions and exhibits higher activity for the oxidation of methanol [59,60]. However, the over potential value of 8 wt% rGO-NiO/CuO MOF is low from 1 wt% and NiO/CuO MOF and high from 2, 3, 4, 5 wt%; these results illustrate a good correspondence with the CV results as they show low current density because of agglomeration of rGO sheets that results in lower surface area and may hinder the ions from reaching the electrode surface.…”

N, S and Transition-Metal Co-Doped Graphene Nanocomposites as High-Performance Catalyst for Glucose Oxidation in a Direct Glucose Alkaline Fuel Cell

“…A large number of studies have shown that transition metals (Ni Co Fe Cu) and their oxides (NiO, Co 3 O 4 and CuO) exhibit good electrocatalytic activity and become a substitute for precious metals. Sarwar et al [ 13 ] prepared a Co-Ni/graphene composite catalyst and tested it in a methanol fuel cell. It is found that increasing the concentration of nickel in the composite catalyst can significantly promote the oxidation reaction of methanol.…”

Development of an Efficient Non‐Noble Metal Based Anode Electrocatalyst to Promote Methanol Oxidation Activity in DMFC

“…Graphene coated Co-Ni 4 with its maximum current density of 22.5 mA cm À 2 and minimum resistance and tafel slope prove to be a good catalyst for oxidation process in alkaline medium. [40] Co 3 O 4 /N-rGO synthesized by Liang et al exhibit excellent activity for oxygen reduction (ORR) and oxygen evolution reaction (OER). In OER current density of 10 mA cm À 2 is delivered at 1.54 V (vs RHE) while in ORR half wave potential was found to be 0.83 V at 1600 rpm as a result of four electron transfer process measured by RDE [41] .…”