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Hydrogen was produced by methanol decomposition over cold-rolled foils of intermetallic compound Ni 3 Al which is known as an excellent high-temperature structural material. We found high catalytic activity and selectivity for methanol decomposition in flat cold-rolled Ni 3 Al foils. The catalytic activity was enhanced above 713 K by the spontaneous formation of fine Ni particles dispersed on carbon nanofibers during the reaction, resulting in high catalytic performance. The results demonstrate that the Ni 3 Al foils can be used both as catalyst precursors and as structural materials of microreactors for hydrogen production.

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In this study, the effect of Ag or Sb addition on the thermoelectric properties of PbTe including the Seebeck coefficient, the electrical resistivity, and the thermal conductivity, was studied in the temperature range from 323 to 723 K. The major carriers in the Ag-doped and the Sb-doped PbTe are holes and electrons, respectively. A degenerate semiconductor behavior in the electrical transport properties was observed in the Ag-doped, whereas the semi-metallic in the Sb-doped. It was suggested from the results of the Hall effect measurement and the Seebeck coefficient that the effective mass was significantly altered by the Sb-doping. The maximum dimensionless figure of merit, ZT, of Pb1−xAgxTe and Pb1−xSbxTe (x=0.1) alloys showed 0.27 and 0.62 at 723 K, respectively. Based on the analysis of the Seebeck coefficient of the Ag or the Sb-doped PbTe, the interaction between Ag and Sb in PbTe, as expected in the AgPbmSbTem+2 (LAST-m), may be supposed.

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