Development of a high performance air cathode for the direct methanol/air fuel cell
The objective of this contract was to produce an oxygen/air cathode delivering 50 mA/cm2 at 0.8 V(RHE) using a platinum loading of 0.5 mg/cm2 in aqueous H(2)SO(4) at 60 C. Testing was carried out using a computerised test programme involving cyclic voltametry and steady-state techniques. The performance of the porous electrodes was compared largely with the behaviour of platinised platinum - not E[O(2)(reversible)] as the oxygen electrode is a highly irreversible system at potentials close to its reversible value. The effect of many variables, e.g. O(2) pressure, Pt loading, PTFE content, temperature, other metals (e.g. Au rather than Pt), solution pH, layer thickness, was examined, but at no stage was good O(2) reduction performance attained at 0.8 V(RHE). Recent results suggest that there are significant potential (iR) losses at the Pt/C interface. Current performance with air is about 25 mA/cm2 at 0.7 V(RHE) using 0.2 mg/cm2 of Pt. Even this level of performance is quite difficult to attain using electrolytes of higher pH.
Bibliographic Reference: EUR 12466 EN (1989) 29 pp., MF, ECU 4, blow-up copy ECU 5
Record Number: 199010358 / Last updated on: 1994-12-01
Original language: en
Available languages: en