Effect of Pd loading on the catalytic properties of molybdenum oxides for the isomerization of heptane
Effect of Pd loading on the catalytic properties of molybdenum oxides for the isomerization of heptane
复制标题
DOI：
10.1016/s0926-860x(98)00228-2
复制
发表时间：
1999-01-11
影响因子：
5.5
通讯作者：
Takahashi, N
中科院分区：
文献类型：
--
作者：
Matsuda, T;Uchijima, F;Takahashi, N
在大气压、523 K 条件下研究了含 Pd 和不含 Pd 的 MoO3 对庚烷异构化的催化性能。 Pd/MoO3的异构化活性随着H-2周期的增加而增加。 623 K 时还原，还原 36 小时后几乎保持恒定。尽管在 Pd 存在下 MoO3 的还原性显着提高，但这种行为几乎与 MoO3 相同。还原后的 Pd/MoO3 的活性是 MoO3 的 2.5 倍。 MoO3和Pd/SiO2的混合物表现出与Pd/MoO3相似的催化性能，表明氢溢出的重要作用。发现 H-2 还原增加了 MoO3 的表面积，特别是在 Pd 存在的情况下。还原的 Pd/MoO3 的异构化活性取决于最多 0.01 mol% 的 Pd 负载量。从这些结果中我们得出结论，Pd/MoO3 的高异构化活性可归因于其较大的表面积以及 Pd 促进脱氢-氢化步骤。 (C) 1999 Elsevier Science B.V. 保留所有权利。
The catalytic properties of MoO3 with and without Pd for the isomerization of heptane have been investigated at 523 K under atmospheric pressure. The isomerization activity of Pd/MoO3 increased with the period of H-2. reduction at 623 K, and became almost constant after 36 h reduction. This behavior was almost the same as that of MoO3, although the reducibility of MoO3 was markedly improved in the presence of Pd. The reduced Pd/MoO3 was al,out 2.5 times as active as the MoO3. The mixture of MoO3 and Pd/SiO2 exhibited a similar catalytic performance to Pd/MoO3, indicating the important role of hydrogen spillover. H-2 reduction was found to increase the surface area of MoO3, especially in the presence of Pd. The isomerization activity of reduced Pd/MoO3 was dependent on the amount of Pd loading up to 0.01 mol%. We conclude from these results that the high isomerization activity of Pd/MoO3 can be attributed to its large surface area as well as to the promotion of dehydrogenation-hydrogenation steps by Pd. (C) 1999 Elsevier Science B.V. All rights reserved.