HIGH POWER DENSITY LOW PT LOADING ANION EXCHANGE MEMBRANE - DIRECT CRUDE GLYCEROL FUEL CELLS

摘要

Biofuels are expected to share a big portion in our future energy landscape. The current production levels of biodiesel in the US and Europe are 108 and 2 u001f109 L/year, and are expected to double in the near future. With biodiesel manufacturing, around 10 wt.% crude glycerol will be generated as a very cheap residual ($0.74- 0.89/gallon). How to economically utilize the crude glycerol has become a challenging problem.[1] We have studied electro-catalytic oxidation of glycerol in high pH media, [2-4] and recently we obtained a high-performance anion exchange membrane - direct crude glycerol fuel cell: 265 mW/cm2 with a Pt/carbon nanofibers (CNFs, with 1.0 mg/cm2 anode) anode catalyst, a Fe-based cathode catalyst (3.0 mgcat./cm2 cathode) and a commercial AEM (Tokoyama A901, 10 μm) at 80 oC and ambient O2 feeding; 203 mW/cm2 at 80oC and ambient air feeding, as shown in the Figure 1. The crude glycerol contains 88 wt.% glycerol, and was obtained directly from soybean biodiesel production. Such a high performance is three orders of magnitude higher than those of other biofuel cells with enzyme catalysts (10-100 μW/cm2), and comparable or even higher than that of well-developed methanol/ethanol-fueled low temperature fuel cells where much greater (sometime 10 times) precious metal loading is required. More details in the electrocatalytic reactions and fuel cell operations will be presented.