A factorial design analysis of (+)-pulegone electrocatalytic hydrogenation

A 24 factorial design was used to analyse the influence of four factors on the electrocatalytic hydrogenation (ECH) of (+)-pulegone, using a nickel sacrificial anode (ECH-SA). The four factors were co-solvent (H2O/MeOH or H2O/ethylene glycol (1:1)), temperature (25 °C or 50 °C), cathodic material (Cu or Fe/Ni (64:36) alloy) and 0.2 mol L−1 supporting electrolyte (NH4Cl or NH4Ac). The analysis of the results showed that changing the temperature does not have a significant effect on the studied system (ECH-SA). The most significant factors were co-solvent and supporting electrolyte, with MeOH and NH4Cl giving the best results. The (+)-pulegone hydrogenation performance on Cu or Fe/Ni cathode surfaces (recovered with nickel) was similar, showing that the cathodic matrix presents a less significant effect in the ECH-SA process, although it plays an important role in the initial nickel deposit formation affecting its morphology (shape, size, homogeneity and spacing).