A direct fuel cell comprises a cathode comprising electroactive catalyst material; and an anode assembly comprising an anode having a porous layer and electroactive catalyst material in the porous layer. The electrode characteristics of the anode assembly are selected so that fuel supplied to the anode is reacted within the anode so that cross-over from the anode to the cathode does not have more than a 10% negative effect on voltage or a 25 mV voltage loss when at peak power and steady state conditions. The anode and cathode each have a first major surface facing each other in non-electrical contact and without a microporous separator or ion exchange membrane therebetween.