ЕЛЕКТРОКАТАЛІЗ З УЧАСТЮ АМОРФНИХ МЕТАЛЕВИХ ЕЛЕКТРОДІВ

Abstract

The effect of chemical composition of amorphous metal electrodes with different elemental composition (i.e. Al87.0Y5.0Ni8.0, Fe80.0Si6.0B14.0, Fe78,5Ni1.0Mo0.5Si6.0B14.0, Fe81,0Ni1.0Nb0.5Mo0.5Si3.0B14.0, Fe73,1Cu1.0Nb3.0Si15.5B7.4) on their electrocatalytic activity in the reactions of the decomposition of peroxide –O–O– bonds in hydrogen peroxide H2O2 and organic oligoperoxide compounds based on vinyl acetate, 2-tert-butyl peroxy-2-methyl-5-hexen-3-yne and maleic anhydride was studied. The electrochemical reduction of H2O2 and organic oligoperoxsde on AMA-electrodes by cyclic voltammetry is investigated. The dependencies of the rate of electrocatalytic processes on the concentration of supporting electrolyte, the rate of scanning of potential, the concentration of depolarizer and the duration of the initial spontaneous (in the absence of external potential) interaction of the peroxides compounds with the electrode surface were investigated. The rate constants of the decomposition of –O–O– bonds in peroxides of different structure were determined. In the case of the electrocatalytic AMA electrode Al87.0Y5.0Ni8.0, the process of dissociation of –O–O– bonding by the reductive mechanism is the most probable: In the case of AMA electrodes based on Fe (especially Fe73,1Cu1.0Nb3.0Si15.5B7.4) the decomposition of –O–O– bonds follows preferential oxidation mechanism: . Due to their high absorption ability, oligoperoxide molecules can undergo conformational changes on the surface of the electrode. This affects the stability of the peroxide bond significantly. The functional groups of oligoperxides show affinity to localized electrons on the electrode surface. This leads to the elongation of the –O–O– bond and facilitates the fragmentation of the oligomers. The amorphous alloys Fe73,1Cu1.0Nb3.0Si15.5B7.4 and Fe81,0Ni1.0Nb0.5Mo0.5Si3.0B14.0 have a higher catalytical activity in decomposition of H2O2.