Fuel cells--II. Propane and propylene on Adams' platinum catalyst

Abstract

In order to control the quantity of previously adsorbed hydrogen in fuel electrodes to be used with hydrocarbons, the use of Adams' platinum catalyst was investigated. Preferred procedures for electrode preparation were developed. Adams' platinum oxide powder was intimately mixed with a silver powder and pressed to form a disk, which, fixed within a cell, was reduced with hydrogen in glacial HOAc and then treated with a water-proofing wax solution. Reduction could be stopped at a definite stage and the reduced electrode could be protected from air throughout all manipulative and measuring procedures. The potential behaviour of 15 electrodes reduced to differing degrees was studied in helium, propane, propylene and hydrogen at 80[deg]C.During flushing with propylene, the open-circuit potential increased quite rapidly after an induction period, which was related to the original degree of electrode reduction. The steady potential reached increased with the degree of reduction. The potential of an electrode initially saturated with hydrogen gradually decreased with propylene flushing, approaching a steady value.The good discharge behaviour observed for propylene far exceeded that due to hydrogen adsorbed during electrode preparation. Propylene flushing for more than 20 h was necessary to reach a steady potential. On interruption of the discharges, the potential returned to almost the initial potential. The steady potential may represent an equilibrium potential between propylene, electrode and electrolyte, and may be called a "propylene potential".