Anode electro-catalysts for direct dimethyl-ether fuel cell (DDFC), Pt/C, PtRu/C (1∶1) and PtSn/C (3∶2), were prepared by chemical impregnation-reductio n method with formaldehyde as the reductant. DME electro-oxida...Anode electro-catalysts for direct dimethyl-ether fuel cell (DDFC), Pt/C, PtRu/C (1∶1) and PtSn/C (3∶2), were prepared by chemical impregnation-reductio n method with formaldehyde as the reductant. DME electro-oxidation and adsorptio n at Pt electrode and Pt electro-catalysts were investigated by Cyclic Voltammet ry(CV), Quasi-steady state polarization and Gas Chromatography(GC). CV showed th at there were two current peaks of DME electro-oxidation at Pt electrode around 0.8V (vs RHE); DME was adsorbed at Pt electrode more weakly and slowly than oxyg en, methanol, even hydrogen; the onset potential of DME oxidation was 50mV less than that of methanol, and DME peak potential 110 mV lower, thus more advantageo us for using in fuel cells than methanol. GC showed that small amount of HCHO wa s generated during DME electro-oxidation. The mechanism of DME electro-oxidation was proposed. Among the three electro-catalysts (Pt/C, PtRu/C and PtSn/C), Pt a lloy catalysts, especially PtRu/C, showed a higher performance toward DME electr o-oxidation, as in the case of methanol. Temperature experiments showed that bot h DME electro-oxidation and adsorption on Pt and Pt alloy catalysts were favored with increased temperature.展开更多
文摘Anode electro-catalysts for direct dimethyl-ether fuel cell (DDFC), Pt/C, PtRu/C (1∶1) and PtSn/C (3∶2), were prepared by chemical impregnation-reductio n method with formaldehyde as the reductant. DME electro-oxidation and adsorptio n at Pt electrode and Pt electro-catalysts were investigated by Cyclic Voltammet ry(CV), Quasi-steady state polarization and Gas Chromatography(GC). CV showed th at there were two current peaks of DME electro-oxidation at Pt electrode around 0.8V (vs RHE); DME was adsorbed at Pt electrode more weakly and slowly than oxyg en, methanol, even hydrogen; the onset potential of DME oxidation was 50mV less than that of methanol, and DME peak potential 110 mV lower, thus more advantageo us for using in fuel cells than methanol. GC showed that small amount of HCHO wa s generated during DME electro-oxidation. The mechanism of DME electro-oxidation was proposed. Among the three electro-catalysts (Pt/C, PtRu/C and PtSn/C), Pt a lloy catalysts, especially PtRu/C, showed a higher performance toward DME electr o-oxidation, as in the case of methanol. Temperature experiments showed that bot h DME electro-oxidation and adsorption on Pt and Pt alloy catalysts were favored with increased temperature.
