MnCo2O4/NiCo2O4/rGO as a Catalyst Based on Binary Transition Metal Oxide for the Methanol Oxidation Reaction

Abstract

The demands for alternative energy have led researchers to find effective electrocatalysts in fuel cells and increase the efficiency of existing materials. This study presents new nanocatalysts based on two binary transition metal oxides (BTMOs) and their hybrid with reduced graphene oxide for methanol oxidation. Characterization of the introduced three-component composite, including cobalt manganese oxide (MnCo2O4), nickel cobalt oxide (NiCo2O4), and reduced graphene oxide (rGO) in the form of MnCo2O4/NiCo2O4/rGO (MNR), was investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), and energy-dispersive X-ray (EDX) analyses. The alcohol oxidation capability of MnCo2O4/NiCo2O4 (MN) and MNR was evaluated in the methanol oxidation reaction (MOR) process. The crucial role of rGO in improving the electrocatalytic properties of catalysts stems from its large active surface area and high electrical conductivity. The alcohol oxidation tests of MN and MNR showed an adequate ability to oxidize methanol. The better performance of MNR was due to the synergistic effect of MnCo2O4/NiCo2O4 and rGO. MN and MNR nanocatalysts, with a maximum current density of 14.58 and 24.76 mA/cm2 and overvoltage of 0.6 and 0.58 V, as well as cyclic stability of 98.3% and 99.7% (at optimal methanol concentration/scan rate of 20 mV/S), respectively, can be promising and inexpensive options in the field of efficient nanocatalysts for use in methanol fuel cell anodes.

Research progress of Co-based spinel oxide materials for direct methanol fuel cells

“…Compared with monometallic oxides, the chemical properties of composites formed with other materials can be improved due to the synergistic effect between the materials. Askari et al 100 The maximum current densities of MN and MNR nanocatalysts are 14.58 and 24.76 mA cm À2 , the overpotential are 0.6 and 0.58 V, and the cyclic stabilities are 98.3% and 99.7%, 98 . The overall formation mechanism of MnCo 2 O 4 microspheres (c).…”

“…It has broad application prospects in different fields. 6,[58][59][60][89][90][91]100,109,[121][122][123][124][125] The research results show that the dispersion of transition metal compounds can be improved by combining them with carbon materials, and the agglomeration or sintering of active components can be avoided. Second, the resistance between active nanocrystals can be significantly reduced to improve the electron transport performance of the composite.…”

“…Compared with monometallic oxides, the chemical properties of composites formed with other materials can be improved due to the synergistic effect between the materials. Askari et al 100 studied a novel nano-catalyst MnCo 2 O 4 /NiCo 2 O 4 /rGO (MNR) for MORs based on two binary transition metal oxides (BTMOs) and their compounds with rGO. The alcohol oxidation capacity of MnCo 2 O 4 /NiCo 2 O 4 (MN) and MNR was evaluated during the MOR.…”

Composite electrodes with superior catalytic activity in methanol electro-oxidation fabricated using ternary NiO–CuO–ZnO mixed metal oxides

“…Current research has examined binary and ternary mixed metal oxides for alcohol oxidation. Previously reported mixed metal oxides such as La 2 NiO 4 , 17 CoMoO 4 19 MgCo 2 O 4 35 NiCo 2 O 4 36 MnNi 2 O 4 37 and MnCo 2 O 4 38 have been used in MeOH and EtOH electro-oxidation reactions. Both methanol and ethanol have a comparatively simple structure, low cost and are easily available due to their abundance in nature.…”

Synthesis of Nanocomposites and Catalysis Applications II

“…Also, photocatalysts show promising results in the decomposition of organic dyes, such as methylene blue or rhodamine B, as shown in [9,10]. Electrocatalytic nanocomposites, on the other hand, facilitate electrochemical reactions by providing efficient charge transfer pathways, as shown in [11] for MnCo 2 O 4 /NiCo 2 O 4 /rGO and [12] for ZrO 2 /NiO/rGO systems.…”