A New Kinetic-Mechanistic Approach to Elucidate Formaldehyde Electrooxidation on Ni/Al LDH Nanoparticles Modified Carbon Ceramic Electrode

In the present study, electrocatalytic oxidation of formaldehyde was investigated on Ni/Al Layered double hydroxide nanoparticles modified carbon ceramic (Ni/Al LDH/NMCC) electrode in alkaline media (i.e. NaOH 0.1 M).The process of oxidation involved and its kinetics were established by using cyclic voltammetry, chronoamperometry as well as steady state polarization measurements. The cyclic voltammogram of the resulting modified electrode prepared under optimum conditions, shows a good redox behavior ofNi(III)/Ni(II) couple at the surface of these electrodes can be observed. A new mechanism based on the electrochemical generation of Ni(III) active sites and their subsequent consumption by the formaldehyde in question was also investigated. For Ni/Al LDH/NMCC electrode, the transfer coefficient (α), the number of electrons involved in the ratedetermining step (nα) and the catalytic rate constant (k) for modified electrode were calculated as 0.43,1 and 0.6536×104 cm3mol–1 s–1 respectively. The modified electrode shows a stable and linear response in the concentration range of 0.01 to 0.1 mol L−1 with acorrelation coefficient of 0.9906.