New method for monitoring of the oxygen reduction process in aqueous solutions

Abstract

Composite electrode material based on NaX zeolite and silver dispersed both inside zeolite cavities and between the zeolite crystals, in nitrogen purged 0.1M NaOH solution, yielded the cyclic voltammograms corresponding to silver of very developed real surface area. The same electrode material in oxygen saturated 0.1M NaOH solution, by use of rotating disc technique, yielded the voltammograms which indicate 4e-route of oxygen reduction reaction. Therefore, this composite may be considered as promising one for determination of oxygen in aqueous solutions. Proceeding from the fact that bulk silver is fair electrocatalyst for oxygen reduction in alkaline solution, in this paper we impregnated zeolite NaX with Ag-acetylacetonate/ acetone solution and decomposed Ag-acetylacetonate, in order to obtain finely dispersed silver based catalyst for oxygen reduction. .

Kompozitni elektrodni materijal na bazi NaX zeolita i srebra dispergovanog unutar kaveza zeolita i između kristala zeolita, u rastvoru 0.1M NaOH, daje ciklične voltamograme koji odgovaraju srebru sa vrlo razvijenom površinom. Isti elektrodni materijal u 0.1M NaOH rastvoru zasićenom kiseonikom, uz pomoć tehnike rotirajućeg diska, daje voltamograme koji odgovaraju 4e-mehanizmu reakcije redukcije kiseonika. Zato se ovaj kompozit može smatrati pogodnim za monitoring kiseonika u vodenim rastvorima. Polazeći od činjenice da je srebro dobar elektrokatalizator za redukciju kiseonika u alkalnim rastvorima, mi smo impregnirali zeolit NaX rastvorom Agacetilacetonata/acetona i rastvorenim Ag-acetilacetonatom, da bismo dobili katalizator od fino dispergovanog srebra za redukciju kiseonika. .