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PdAu/YSZ composite hydrogen separation membranes with enhanced stability in the presence of CO
Journal of Membrane Science ( IF 8.4 ) Pub Date : 2020-10-01 , DOI: 10.1016/j.memsci.2020.118371
Sean-Thomas B. Lundin , Neil S. Patki , Zhenyu Zhang , Thomas F. Fuerst , Colin A. Wolden , J. Douglas Way

Abstract The effects of gold concentration on the carbon tolerance of palladium-based composite membranes was studied under the presence of high CO concentrations. Membranes with PdAu compositions up to 41% Au by mass were exposed to 50/50H2/CO gas atmospheres and both hydrogen flux and permeate purity were monitored over time. The highest gold concentration (41 wt%) had no measurable degradation in membrane performance in terms of either hydrogen permeate purity or hydrogen permeation flux during the 48 h exposure; in contrast, the pure palladium membrane suffered total degradation during the same exposure time. Furthermore, for lower gold concentrations, X-ray diffraction patterns suggested that carbon entered the membrane film and could be removed by exposure to hydrogen and a non-CO containing gas mixture over time; however, removal of the carbon adversely affected hydrogen permeate purity. Interestingly, some of the observed hydrogen permeate purity decline could be reversed upon re-exposure to the CO gas mixture. It is hypothesized that carbon loading in the palladium films causes lattice expansion and may even fill pore defects, thus lowering non-hydrogen leaks through the Pd membrane films. This study suggests that a membrane exposed to a CO mixture should not be cycled between CO and non-CO environments, but rather run continuously for best performance. Additionally, the choice of Pd-alloy metal and composition should be considered in regard to its carbon solubility to best predict lifetime performance.

中文翻译:

在 CO 存在下具有增强稳定性的 PdAu/YSZ 复合氢分离膜

摘要 研究了在高 CO 浓度下金浓度对钯基复合膜碳耐受性的影响。PdAu 组成高达 41% Au 质量的膜暴露在 50/50H2/CO 气体气氛中,并且随着时间的推移监测氢通量和渗透纯度。在 48 小时暴露期间,最高金浓度 (41 wt%) 在氢渗透纯度或氢渗透通量方面没有可测量的膜性能下降;相比之下,纯钯膜在相同的暴露时间内完全降解。此外,对于较低的金浓度,X 射线衍射图表明碳进入了膜,随着时间的推移,碳可以通过暴露于氢气和不含一氧化碳的气体混合物中去除;然而,碳的去除不利地影响了氢气渗透纯度。有趣的是,一些观察到的氢气渗透纯度下降可以在重新接触 CO 气体混合物后逆转。据推测,钯膜中的碳负载会导致晶格膨​​胀,甚至可能填充孔隙缺陷,从而降低非氢通过 Pd 膜的泄漏。这项研究表明,暴露于 CO 混合物的膜不应在 CO 和非 CO 环境之间循环,而是应连续运行以获得最佳性能。此外,Pd 合金金属和成分的选择应考虑其碳溶解度,以最好地预测寿命性能。一些观察到的氢气渗透纯度下降可以在重新接触 CO 气体混合物后逆转。据推测,钯膜中的碳负载会导致晶格膨​​胀,甚至可能填充孔隙缺陷,从而降低非氢通过 Pd 膜的泄漏。这项研究表明,暴露于 CO 混合物的膜不应在 CO 和非 CO 环境之间循环,而是应连续运行以获得最佳性能。此外,Pd 合金金属和成分的选择应考虑其碳溶解度,以最好地预测寿命性能。一些观察到的氢气渗透纯度下降可以在重新接触 CO 气体混合物后逆转。据推测,钯膜中的碳负载会导致晶格膨​​胀,甚至可能填充孔隙缺陷,从而降低非氢通过 Pd 膜的泄漏。这项研究表明,暴露于 CO 混合物的膜不应在 CO 和非 CO 环境之间循环,而是应连续运行以获得最佳性能。此外,Pd 合金金属和成分的选择应考虑其碳溶解度,以最好地预测寿命性能。这项研究表明,暴露于 CO 混合物的膜不应在 CO 和非 CO 环境之间循环,而是应连续运行以获得最佳性能。此外,Pd 合金金属和成分的选择应考虑其碳溶解度,以最好地预测寿命性能。这项研究表明,暴露于 CO 混合物的膜不应在 CO 和非 CO 环境之间循环,而是应连续运行以获得最佳性能。此外,Pd 合金金属和成分的选择应考虑其碳溶解度,以最好地预测寿命性能。
更新日期:2020-10-01
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