New Insights into the Electrocatalytic Mechanism of Methanol Oxidation on Amorphous Ni-B-Co Nanoparticles in Alkaline Media

Abstract

Despite an increased interest in sustainable energy conversion systems, there have been limited studies investigating the electrocatalytic reaction mechanism of methanol oxidation on Ni-based amorphous materials in alkaline media. A thorough understanding of such mechanisms would aid in the development of amorphous catalytic materials for methanol oxidation reactions. In the present work, amorphous Ni-B and Ni-B-Co nanoparticles were prepared by a simple chemical reduction, and their electrocatalytic properties were investigated by cyclic voltammetry measurements. The diffusion coefficients (D0) for Ni-B, Ni-B-Co0.02, Ni-B-Co0.05, and Ni-B-Co0.1 nanoparticles were calculated to be 1.28 × 10−9, 2.35 × 10−9, 4.48 × 10−9 and 2.67 × 10−9 cm2 s−1, respectively. The reaction order of methanol in the studied transformation was approximately 0.5 for all studied catalysts, whereas the reaction order of the hydroxide ion was nearly 1. The activation energy (Ea) values of the reaction were also calculated for the Ni-B and Ni-B-Co nanoparticle systems. Based on our kinetic studies, a mechanism for the methanol oxidation reaction was proposed which involved formation of an electrocatalytic layer on the surface of amorphous Ni–B and Ni-B-Co nanoparticles. And methanol and hydroxide ions could diffuse freely through this three-dimensional porous conductive layer.

Progress toward a better understanding of the urea oxidation by electromediation of Ni(III)/Ni(II) system in alkaline media

“…Here, 𝐸 𝑎,𝐻𝐶𝑅 is estimated to be 49.3 kJ.mol -1 . The order of magnitude is substantially close to that of the oxidation of methanol on nickel electrode [61]. Note that this 𝐸 𝑎,𝐻𝐶𝑅 value is relatively low, which means that the reaction Eq.…”

Electro-oxidation Reaction of Methanol over Reducible Ce1–x–yNixSryO2−δ: A Mechanistic Probe of Participation of Lattice Oxygen

“…The temperature varied from 25 to 50 °C with a gap of 5 °C in 0.5 M NaOH and 0.5 M MeOH electrolyte solution. The activation energy ( E a ) was obtained from the slope of Figure . − …”

Review and Perspective of Nickel and Its Derived Catalysts for Different Electrochemical Synthesis Reactions in Alkaline Media for Hydrogen Production

“…36 In alkaline medium, Ni, Ni 2+ , and Ni 3+ redox centers could easily be converted to active species, accelerating ESR. 37 In the early 1970s, Fleischmann et al 38 used nickel anodes for electrochemical oxidation of some organic compounds in base and found alcohol oxidation catalyzed by NiOOH on Ni-based materials is much slower compared to the oxidation of Ni(OH) 2 to NiOOH. 39 Thereafter, several Ni-based electrocatalysts were designed such as Ni complexes, 40 Ni(OH) 2 , 41 and different Ni alloys, 42 as well as carbon-supported Ni catalysts.…”

“…Having good catalytic activity and relatively less poisoning property, nickel is one of the most popular non-noble catalysts for ESR . In alkaline medium, Ni, Ni 2+ , and Ni 3+ redox centers could easily be converted to active species, accelerating ESR . In the early 1970s, Fleischmann et al used nickel anodes for electrochemical oxidation of some organic compounds in base and found alcohol oxidation catalyzed by NiOOH on Ni-based materials is much slower compared to the oxidation of Ni­(OH) 2 to NiOOH .…”