Electrochemical cell system for voltammetry of high purity solvents

A two-compartment cell system was designed to carry out high purity electro chemical experiments. Features of this cell include a monolithic quartz bod y, quartz isolation frit, pretreated platinum electrode, hydrogen reference electrode, snap-on cell tops, purified "type I" water, high purity supply gases, fluoropolymer tubing, and gas-tight cell integrity. An advantage of this design is the allowance for internal pre-electrolysis of the test solu tion. The system was quality tested by obtaining cyclic voltammograms of 0. 5 molar sulfuric acid solution. To demonstrate its utility for high purity work, novel cyclic voltammograms of type I water were obtained with a plati num microelectrode in the absence of electrolyte. The water voltammograms e xhibited three electroactive features: reduction potential limit near E=-0. 2 V versus r.h.e. (H-2), oxidation potential limit near E=+1.6 V (O-2), and one surface reduction peak at E=+0.4 V. Thus, the voltammetric "potential window" for water was determined to be 1.8 V. (C) 2000 American Institute o f Physics. [S0034-6748(00)03702-3].