A High Catalyst-Utilization Electrode for Direct Methanol Fuel Cells

• A novel anode structure with an unevenly distributed catalyst is proposed.
• The catalyst is unevenly distributed along the in-plane direction.
• The new anode structure allows a reduced catalyst loading.
• The new anode structure improves the utilization of the catalyst.

In this study, a simple method is devised to investigate the local current distribution of the anode of a direct methanol fuel cell (DMFC). It is shown that the local current decreases along the methanol flow direction as a result of the decreased methanol concentration along the same direction during discharge. This finding suggests that the catalyst loading along the flow direction needs to be distributed by following the same trend as the distribution of methanol concentration to achieve high catalyst utilization. In line with this idea, we propose and fabricate a novel anode structure that enables the catalyst loading to be reduced along the methanol flow direction. The fuel cell performance characterization demonstrates that the new anode with uneven catalyst loading matches the performance of the conventional anode involving an evenly distributed catalyst, but the total amount of catalyst loaded in the new anode is substantially reduced.