Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9607789 | Applied Catalysis A: General | 2005 | 7 Pages |
Abstract
Steam reforming of methanol (SRM) was carried out at 250 °C over CuO/CeO2 and CuO/ZrO2 catalysts with various CuO contents and water/MeOH ratios in a flow reaction system. The 80 wt.% CuO/ZrO2 gave the highest activity, and the optimum water/MeOH ratio was 1.5. The oxidation states of Cu species in post-reaction catalyst depended upon CuO contents and the water/MeOH ratio. The starting copper compounds were CuO in all cases, and the copper in almost all catalysts was reduced to metallic Cu. Cu2O appeared in 80 and 90 wt.% CuO/ZrO2 when water/MeOH ratios were above 1 irrespective of reducing atmospheres. The reduction behavior of the 80 wt.% CuO/ZrO2 catalyst with hydrogen was investigated by XANES technique in an in situ cell. In the narrow temperature range of 180-200 °C, CuO was reduced to metallic Cu via the intermediate Cu2O. The Fourier transform magnitude of K-edge Zr of 80 wt.% CuO/ZrO2 showed that the configuration of zirconium in the catalysts was very similar to that of monoclinic zirconia. The Debye rings of 80 wt.% CuO/ZrO2 and 80 wt.% CuO/CeO2 catalysts showed that zirconia was less coagulated at 300 °C than CeO2; heat resistance of ZrO2 is higher than that of CeO2. BET surface area of 80 wt.% CuO/ZrO2 was 85.3 m2/g, and that of 80 wt.% CuO/CeO2 was 46.0 m2/g, suggesting that ZrO2 in the catalyst has micro crystallites and is highly dispersed.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Catalysis
Authors
Hisayuki Oguchi, Hiroyoshi Kanai, Kazunori Utani, Yasuyuki Matsumura, Seiichiro Imamura,