Kinetic Investigations of Glycerol Oxidation Reaction on Ni/C

This study evaluates the electrochemical oxidation of glycerol using a nickel-supported catalyst under several well-defined experimental conditions. The influence of scan rate, temperature, glycerol, and NaOH concentrations were systematically investigated. The slope of the log-log relationship of the anodic peak current for glycerol oxidation as a function of the scan rate indicates that the electrochemical glycerol oxidation is a complex mechanism partially limited by diffusion-controlled process. This is in agreement with the temperature effect on glycerol oxidation, since the slope value associated with the relationship between the logarithm of the current density of the anodic peak and the inverse of temperature also indicates a diffusion process. When the glycerol concentration increases, the peak associated to its oxidation also increases, but it seems to reach a limit. This behavior was associated with two main effects, i.e., the saturation of the active catalytic sites on the electrode surface and the change in the glycerol oxidation mechanism as demonstrated by FTIR spectroscopic measurements.