Development of Hydrogen-Oxygen Fuel Cells Based on Anion-Exchange Electrolytes and Catalysts with Reduced Platinum Content.

Abstract

Studies have been carried out to optimize the composition, formation technique and test conditions of membrane electrode assemblies (MEA) of hydrogen-oxygen anion-exchange membranes fuel cells (AEMFC), based on Fumatech anion-exchange membranes. A non-platinum catalytic system based on nitrogen-doped CNT (CNTN) was used in the cathode. PtMo/CNTN catalysts with a reduced content of platinum (10-12 wt.% Pt) were compared with 10 and 60 wt.% Pt/CNTN at the anode. According to the results of studies under model conditions, it was found that the PtMo/CNTN catalyst is significantly superior to the 10 and 60 wt.% Pt/CNTN catalyst in terms of activity in the hydrogen oxidation reaction based on the mass of platinum. The addition of the Fumion ionomer results in minor changes in the electrochemically active surface area and activity in the hydrogen oxidation reaction for each of the catalysts. In this case, the introduction of ionomer-Fumion leads to a partial blocking of the outer surface and the micropore surface, which is most pronounced in the case of the 60Pt/CNTN catalyst. This effect can cause a decrease in the characteristics of MEA AEMFC upon passing from 10PtMo/CNTN to 60Pt/CNTN in the anode active layer. The maximum power density of the optimized MEA based on 10PtMo/CNTN was 62 mW cm-2, which exceeds the literature data obtained under similar test conditions for MEA based on platinum cathode and anode catalysts and Fumatech membranes (41 mW cm-2). A new result of this work is the study of the effect of the ionomer (Fumion) on the characteristics of catalysts. It is shown that the synthesized 10PtMo/CNTN catalyst retains high activity in the presence of an ionomer under model conditions and in the MEA based on it.