XPS Study of the Influence of CO2 on the H2 Flux through a Composite Membrane Made of Palladium and Porous Stainless Steel
XPS Study of the Influence of CO2 on the H2 Flux through a Composite Membrane Made of Palladium and Porous Stainless Steel
复制标题
钯-多孔不锈钢复合膜CO2对H2通量影响的XPS研究
DOI：
10.1252/jcej.09we213
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发表时间：
2010
影响因子：
0.8
通讯作者：
T. Tomida
中科院分区：
文献类型：
--
作者：
M. Katoh;Koichi Chohama;E. Sakata;T. Horikawa;T. Tomida
在多孔不锈钢（PSS）管的外表面上镀上一层钯膜，可以以绝对选择性促进氢气的快速渗透；渗透基于溶液扩散传输机制。碳氢化合物的重整是众所周知的制造氢气的方法。 CH4 干重整是在使用薄钯膜的膜反应器中进行的。在此反应中，已知化学吸附的 CO2 会影响 H2 渗透行为。通过渗透测试和 XPS 研究了对 H2 渗透和膜稳定性的影响。 H2透过Pd膜后，CO2流过膜1h，H2再次透过膜。实验中温度为623、723和823 K，压差为0.1 MPa，进料速率为10 mL/min。用He代替CO2，在相同条件下进行实验。第二次H2渗透后，H2通量随时间增加并达到原来的值。达到原始值所需的时间取决于气体和温度。在 He 流的情况下，所需时间仅为 5 分钟，并且与温度无关。另一方面，在 CO2 流的情况下，在 623 K 和 723 K 或 823 K 下所需的时间分别为 10 分钟和 25 分钟。 CO2 流动后，测量 Pd 膜表面的 XPS 光谱。光谱表明，通过 Pd 表面的氧化，在 Pd 膜上形成了 PdO。 PdO是通过化学吸附CO2形成的，PdO降低了H2的渗透性；然而，PdO 很容易被 H2 流还原为 Pd。当 CH4 干重整实验在 Pd 膜反应器中使用常规 Pt 基催化剂和吹扫气在 873 K 下进行 12 小时时，H2 通量、H2 选择性和 H2 回收率约为 10%。分别为 6 mL/min、98%（不包括吹扫气计算）和 80%。
Plating a Pd membrane on the outer surface of a porous stainless steel (PSS) tube facilitates rapid H2 permeation with an absolute selectivity; the permeation is based on the solution-diffusion transport mechanism. Reforming of carbon hydride is a well-known method of manufacturing H2. CH4 dry reforming is performed in a membrane reactor using a thin Pd membrane. In this reaction, chemisorbed CO2 is known to affect H2 permeation behavior. The effect on H2 permeation and membrane stability were investigated by performing a permeation test and by XPS. After H2 was permeated through the Pd membrane, CO2 was flowed over the membrane for 1 h, and H2 was once again permeated through the membrane. In the experiment, the temperatures were 623, 723, and 823 K, the differential pressure was 0.1 MPa, and the feed rate was 10 mL/min. CO2 was replaced by He and the experiment was performed under the same conditions. After the second H2 permeation, the H2 flux increased with the time and attained its original value. The time required to attain the original value was dependent on the gas and the temperature. In the case of the He flow, the time required was only 5 min and was independent of the temperature. On the other hands, in the case of the CO2 flow, the required times were 10 min and 25 min at 623 K and 723 K or 823 K, respectively. After the CO2 flow, the XPS spectra of the surface of the Pd membrane were measured. The spectra showed that PdO was formed on the Pd membrane by oxidation of the Pd surface. The PdO was formed by chemisorbed CO2, and the H2 permeability was degraded by PdO; however, PdO was easily reduced to Pd by the H2 flow. When the experiment involving CH4 dry reforming was performed in the Pd membrane reactor with conventional Pt-based catalysts and a sweep gas for 12 h at 873 K, the H2 flux, H2 selectivity, and H2 recovery were ca. 6 mL/min, 98% (calculated by excluding the sweep gas), and 80%, respectively.
DOI：
--
发表时间：
2010
期刊：
International Journal of Modern Physics B (印刷中)
影响因子：
--
作者：
M.Katoh;et al.
通讯作者：
et al.