Low and non-platinum electrocatalysts for PEMFCs: Current status, challenges and prospects

Biohydrogen for a New Generation of H2/O2 Biofuel Cells: A Sustainable Energy Perspective

“…Recent publications report on the use of nonnoble-metals for H 2 oxidation. [5,17] Mo and W carbides, metal sulfides, Pd-Ni alloys, and especially Ir-V alloys have been shown to present promising high activity and good stability. For oxygen reduction catalysis, Fe-and Co-porphyrin-based macrocycles, Fe and Mn carbides, nitrides and oxides, and Rubased chalcogenides have been investigated the most; however, none of them compete with the exceptional performance of Pt, especially for use in low-temperature fuel cells.…”

“…These metals are, however, very expensive (average price is 40 E/g against 2 E/g for Ru for example [from http://www.platinum.matthey.com/prices/price-charts/]), are available in low amounts on earth (37 ppb in the Earth's crust), and are nonbiodegradable. Extensive research has aimed at decreasing the Pt content (for a review see [5] ), such as: 1) nanostructuration of the catalysts, [6,7] 2) use of alloys or heterostructures, [8][9] 3) nanostructuration and treatment of the carbon support, [10][11][12][13] 4) use of noncarbon matrixes such as conducting polymers, [14] and 5) use of semiconductive transitionmetals. [15] Furthermore, platinum catalysts are readily poisoned by very low levels of CO and S (0.1 % of CO is sufficient to decrease one hundred fold the catalytic activity of Pt in ten minutes), thus requiring extensive H 2 purification.…”

Trimetallic catalyst based on PtRu modified by irreversible adsorption of Sb for direct ethanol fuel cells

“…The addition of other metals (as an alloy [8][9][10][11][12][13] or by irreversible adsorption [14,15]) to Pt has become the way of tailoring the properties of this metal in order to improve their resistance to the poison formation or its capability for breaking the C-C bonds. The higher performance of bimetallic catalysts toward ethanol oxidation has been attributed to a bifunctional mechanism and to the change of the electronic properties of Pt [16]. In the bifunctional mechanism, the oxidation of the strongly adsorbed intermediates is facilitated by the presence of foreign metal oxides that supply oxygen atoms at lower potentials than in pristine Pt.…”

Highly active nitrogen-doped nanocarbon electrocatalysts for alkaline direct methanol fuel cell

“…Compared to pure hydrogen, which is used in most lowtemperature fuel cells, methanol possesses several advantages like easy storage, transportation, high solubility in aqueous electrolytes and it can be handled by the existing infrastructure [8][9][10]. On the other hand DMFC has also few drawbacks like low electrocatalytic activity for the methanol oxidation reaction, CO poisoning of catalysts and low electrocatalytic activity for oxygen reduction reaction (ORR) on cathode catalyst [11]. The slow reaction rate at the cathode side of the DMFC is usually caused by the methanol crossover through the ion exchange membrane or low intrinsic activity of the ORR, which in the end will reduce the efficiency of the fuel cell.…”