(496c) Metal-Catalyst-Free Fuel Cells with Nanocarbon As Catalysts

Fuel cells are considered as a potential solution to sustainable energy, however their wide spread commercialization have long been hindered by limited reserve and relatively high cost of metal catalysts. Although significant progress has been made to explore non-noble metal catalysts, it remains challenging to replace metal catalysts at the anode side of low temperature fuel cells by non-metal catalysts, thus achieving total removal of the metal catalysts from a fuel cell. We present that 3D graphene prepared by reduction of carbon monoxide with lithium oxide, can serve as as a carbon-only catalyst for fuel cell, electrochemically catalyzing carbohydrazide oxidation reaction efficiently. Muti-walled CNT also outperforms carbon black and 2D graphene in catalyzing carbohydrazide oxidation reaction. Prototypes of anode metal free and completely metal free anion exchange membrane fuel cells with 3D graphene anode catalyst generate peak power density of 75.1 mW cm^-2 and 24.9 mW cm^-2, respectively. In average, 4.9 electrons are electrochemically extracted from one carbohydrazide molecule, indicating the existence of C-N bond cleavage, which is a key factor contributing to high fuel utilization efficiency.