Synthesis and characterization of Ni/NiCo2O4 modified electrode for methanol electro-catalytic oxidation

• Published in: IOP conference series. Materials Science and Engineering 2021-02, Vol.1046 (1)
• Main Authors: Hamdedein, A, El Rouby, W M A, Khan, M D, EL-Deeb, M M, Farghali, A A, Khedr, M H, Revaprasadu, N
• Format: Article
• Language: English
• Subjects: Catalysts; Catalytic oxidation; Corrosion effects; Corrosion rate; Crystallites; Current density; Decay rate; Electrical measurement; Glassy carbon; Methanol; Nickel; Nickel compounds; Oxidation
• ISSN: 1757-8981; 1757-899X
• DOI: 10.1088/1757-899X/1046/1/012027

The present work reports the study of hydrothermally synthesized Ni/NiCo2O4 with different ratios of nickel (10, 20 and 30) %. The crystallite size was decreased from pure nickel cobaltite (NiCo2O4) to the 10, 20 and 30% Ni/NiCo2O4 samples. In a basic media by utilizing the chrono-amperometry method, the electro-chemical behavior and persistence on glassy carbon adjusted electrode was followed across methanol electro-oxidation. It is clearly seen with growing the methanol concentration up to to 2 M, a clear increase of the current density was obtained for the pure nickel cobaltite catalyst which may be related to the increased oxidation at the surface. Scanning electron microscopy (SEM) images of the pure catalyst shows needle-like structures without agglomeration, recording a highly current density of 80 mA/cm2 at 2 M of methanol and scan rate of 60 mV/s. All the tested electrodes show a higher stability hence, the current decayed more slowly with less corrosion impact. Surface modification, barrier and block action effect by Ni on the surface of the catalyst, nearly 80% shortage in the efficiency was observed by using 10 % of Ni. By increasing the ratio to 20 and 30 % the efficiency dropped sharply. Hence, the following order of reactivity was observed: pure nickel cobaltite > 10% Ni-nickel cobaltite > 20% nickel cobaltite> 30% nickel cobaltite, according to their current density values.