A chemically regenerative redox fuel cell. II

Abstract

Our previous paper [1] has described an unconventional chemically regenerative redox fuel cell, including a modest amount of performance data, and has pointed out a number of problem areas. This paper describes additional work and some attempts that have been made to improve the cell performance in several of the problem areas described in the first paper. Two different redox fuel cell systems employing the V²⁺/V³⁺ and Mo³⁺Mo⁴⁺ redox couples as the anolyte, and a new NO ^−/NO₃ catalyst system for VO²⁺ oxidation were explored and described. The reduction of Na₂MoO₄ to Mo⁴⁺ and Mo³⁺ by H₂ in concentrated H₂SO₄ solution was studied in small scale laboratory experiments and discussed. The performance of a redox cell in which H₂ was obtained from the Pd-catalysed decomposition of formic acid, HCOOH, is described and the results of experiments with different membranes are reported. The results of experiments using WC as a hydrogenation catalyst at a temperature of 70–90° C with mixed molybdo-tungsto-silicic acids are reported and discussed.