Deposition of an ultrathin palladium (Pd) coating on SAPO-34 membranes for enhanced H2/N2 separation
Deposition of an ultrathin palladium (Pd) coating on SAPO-34 membranes for enhanced H2/N2 separation
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DOI：
10.1016/j.ijhydene.2020.09.087
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发表时间：
2020-09
影响因子：
7.2
通讯作者：
Ji Jiang;Syed Islam;Qiaobei Dong;Fanglei Zhou;Shiguang Li;Miao Yu
中科院分区：
文献类型：
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作者：
Ji Jiang;Syed Islam;Qiaobei Dong;Fanglei Zhou;Shiguang Li;Miao Yu
氢能因其能量传递效率高、零污染排放等特点而备受关注。分子筛膜具有均匀的、分子大小的孔以及较高的热稳定性和机械稳定性，是一种很有前途的氢分离材料。然而，为了消除合成和后焙烧过程中形成的缺陷，通常需要更厚的膜或改性处理，从而导致气体渗透率较低。在此，我们报道了在SAPO-34膜上沉积超薄钯(Pd)涂层以提高H_2的分离性能。通过在SAPO-34膜上沉积一层超薄的Pd膜，在保持相近的H_2渗透率的情况下，大大提高了H_2/N_2的选择性。这可能归因于H_2在Pd上的解离吸附和缔合脱附，以及H_2在超薄Pd涂层中的快速扩散。我们还注意到，过多的Pd沉积会导致SAPO-34膜出现裂纹，导致膜性能恶化。
Hydrogen energy has attracted great attention due to its properties of high energy transferring efficiency and zero pollution emission. Zeolite membranes are promising candidates for H2separation because of their uniform, molecular-sized pores and high thermal and mechanical stabilities. However, thicker membranes or modification treatments are often necessary to eliminate the defects formed during synthesis and post calcination, leading to low gas permeance. Herein, we reported the deposition of an ultrathin palladium (Pd) coating on SAPO-34 membranes to improve H2separation performance. H2/N2selectivity was greatly increased by deposition of an ultrathin Pd coating on SAPO-34 membranes, while maintaining similar H2permeance. This might be attributed to the dissociative adsorption and associative desorption of H2on Pd, as well as fast diffusion of H2through ultrathin Pd coating. We also noticed that excessive Pd deposition would lead to the formation of cracks on SAPO-34 membranes, leading to deteriorated membrane performance.