ELECTROOXIDATION OF PROPANOL ON HIGHLY PR EFERRED ORIENTATION(220) NICKEL ELECTRODE IN ALKALINE MEDIA

Ni electrode with (220) highly preferred orientation was obtained with potentiostatic electrodeposition in the solution containing 1.0 mol/L NiSO4 and 0.5 mol/L H3BO3. The Ni electrode deposited at -1.25 V for 60 min was examined with X-ray diffaction. It was shown that the Ni el ectrode has a highly preferred orientation with texture degree of 92%. The mechanism and catalytic activities of propanol oxidation on the h ighly preferred orientation (220) Ni electrode were studied with cycli c voltammetry. It was shown that the electrocatalytic activity of the Ni electrode or propanol oxidation is higher than that for isopropanol , The kinetic equation of propanol electrooxidation was derived, The k inetic parameters were measured with polarization curves. The rate con stant [k(1)(E)] for the oxidation of Ni(II) to Ni(III) is 5.25 X 10(-1 3)exp(0.488FE/RT). The rate constant [K-1(E)] for the reduction of Ni( III) to Ni(II) is 2.46 X 10(-4)exp(-0.512FE/RT) and the rate constant (k(2))for the oxidation of propanol by Ni(III) is 5.64 X 10(-6)L . mol (-1)s(-1).