Acta Phys. -Chim. Sin. ›› 1987, Vol. 3 ›› Issue (05): 525 -528 .doi: 10.3866/PKU.WHXB19870515

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THE ELECTRODE PROCESSES OF COPPER ELECTRODEPOSITION FOR PYROPHOSPHATE SOLUTION II. THE STUDY BY ROTATING ELECTRODE METHOD

Qin Erhua; Gu Linying   

  1. Tianjin University; Tianjin
  • Received:1986-03-19 Revised:1986-09-23 Published:1987-10-15

Abstract: Cathodic polarization curves has been measured by means of rotating disc and ring-disc electrodes in cupric pyrophosphate solution. Monovalence pyrophosphoric complex of copper has been detected as intermediate of reduction process. Influence of electrode potential on formation of the intermediate has been observed. By means of rotating disc methode the kinetic current of reduction process has been estamited. It has been found that in more negative potential range contribution of kinetic control yet is appreciable. Based on the polt I_(lim)/ω~(1/2)vs.I_(lim) existence of a preceding chemical process has been evidenced. The following reaction mechanism is proposed
[Cu(P_2O_7)_2]~(6-) <=> [Cu(P_2O_7)]~(2-)+P_2O_7~(4-)
[Cu(P_2O_7)]~(2-)→[Cu(P_2O_7)]~(3-)→Cu+P_2P_7~(4-)