The heterogeneous catalytic redox behaviour of NiS(x) deposited electrodes was investigated with and without benzyl alcohol in KOH solution using cyclic voltammetry and linear sweep voltammetry. The limiting current density for benzyl alcohol oxidation on a NiS(x) electrode was 22 times larger than that on a polished nickel electrode. The experimental results in galvanostatic electrolysis using fractional factorial design showed that the main and interaction effects of benzyl alcohol concentration, temperature, and OH- concentration are the key variables influencing the selectivity of benzaldehyde formation during electrolysis.