New electrocatalysts for the acid methanol fuel cell
Many alloys of non-noble metals with platinum were studied as methanol catalysts, using cyclic voltammetry and current-time transients. One Pt-ternary system was discovered to be more active than any previous catalytic material. At a potential of 300 mV vs. RHE and ambient temperature, a current density of 50 to 70 mA/cm2 was obtained. Investigations by on-line MS and ECTDMS show, in agreement with charge measurements on platinum single crystals, that the methanol adsorbate is a mixture of COH(ad) and CO(ad). The nature of the strongly adsorbed intermediate was studied by in-situ FTIR investigation of polished alloy surfaces. The coverage with CO, poisoning the electrode surface, strongly depends on the type of alloy. Metal porphyrin or polyacrylonitrile based electrocatalysts offer an economic way to obtain oxygen electrodes with selective catalytic behaviour in methanol solution. Teflon-bonded porous carbon electrodes up to a size of 20 cm2 have been tested successfully at ambient temperatures and 60 C. Long duration tests on half cells have been performed over more than 2500 hrs and more than 100 Ah/cm2. Two methanol fuel cells have been built for demonstration.
Bibliographic Reference: EUR 12877 EN (1990) 141 pp., MF, ECU 8, blow-up copy ECU 18.75
Record Number: 199011369 / Last updated on: 1994-12-01
Original language: en
Available languages: en