| Popis: |
A Pd/ZnO sample prepared by the polygonal barrel-sputtering method was tested for the performance in methanol steam reforming in comparison with a similar sample from a conventional wet process.Transmission electron microscopy (TEM) showed that sputtering produced smaller and more uniformly sized Pd nano-particles than the wet process. Steam reforming of methanol was conducted by supplying a gaseous mixture of methanol + H_2O + Ar. In the experiment with the polygonal barrel-sputtering method, H2 generation started at a lower temperature (80 aq than that for the wet process (100 ℃). In addition, H_20 was scarcely consumed at both of the samples when H2 was generated at< 100 ac . These results suggested that the sputtering preparation allowed direct decomposition of methanol to occur easily at less than 100℃, as supported by the observed relationship between the CO/CO_2 generation ratio and the reaction temperature. It should be noted that the smaller Pd particle sizes for the sputtering method were maintained at reaction temperatures up to 150℃. |
