A fuel cell is not an engine. A fuel cell converts chemical energy to electrical energy without going through the intermediate steps heat energy, and mechanical energy. Think of it as a battery that you recharge by pouring new methanol in.
Btw, the link says it runs ~5 hrs on 0.3 litres of 10% methanol. I wonder what the rest is, water? I guess they need a certain concentration to get optimal efficiency on the fuel cell. But it would be nice if you could load it in more concentrated form, and that it mix it to the desired concentration automatically. Just to get more operating time per litre fluid.