TY - JOUR
T1 - Ultrathin layered Pd/PBI–HFA composite membranes for hydrogen separation
AU - Kong, Seong Young
AU - Kim, Da Hye
AU - Henkensmeier, Dirk
AU - Kim, Hyoung Juhn
AU - Ham, Hyung Chul
AU - Han, Jonghee
AU - Yoon, Sung Pil
AU - Yoon, Chang Won
AU - Choi, Sun Hee
N1 - Funding Information:
This study was supported by the New and Renewable Energy Core Technology Program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), with financial resources from the Ministry of Trade, Industry and Energy, Republic of Korea [grant number: 20153010031930, 2MR3100]. Part of this study was also supported by the Youlchon Chemical Co Ltd [2I22610] and the KIST institutional program for the Korea Institute of Science and Technology [2E26590]. The authors would like to thank Ralf Dreher from Fraunhofer for assistance with conducting CO
Publisher Copyright:
© 2017 Elsevier B.V.
PY - 2017
Y1 - 2017
N2 - Generally, Pd membranes used for H2purification are deposited on porous stainless steel (SS) or porous ceramics. These membranes are thick ( > 5 μm) because of the large pore size of the support used; hence, such thick membranes are not cost-effective. In this study, cost-effective, viable ultrathin Pd membranes, which were deposited on a polymer substrate, e.g., polybenzimidazole-4,4′-(hexafluoroisopropylidene)bis(benzoic acid) (PBI–HFA), with a thickness less than 700 nm, were prepared by vacuum electroless plating (VELP). The estimated thickness and effective permeation area of the Pd/PBI–HFA membranes were 130–656 nm and 8.3 cm2, respectively. An optimum Pd/PBI–HFA membrane was deposited after two times activation (A2). Because of the adequate grain size of Pd crystals and thickness, Pd/PBI–HFA exhibited better hydrogen permselectivity than the samples prepared by one and three times activation. Furthermore, the polymer surface treated by the CO2plasma (CO2) and oxidation by H2O2(H) leads to the enhanced selectivity performance of the final Pd/PBI–HFA membrane, caused by the enhanced adhesion between Pd and PBI–HFA. Gas permeation properties of H2, N2, CO2, and CO were evaluated between 35 and 200 °C and pressure differences between 4 and 8 bar. Pd films fabricated by A2-CO2methods exhibited superior performance, as well as excellent αH2/N2 and αH2/CO2 permselectivities of 41.4 and 22.3, respectively, at 150 °C and 8 bar, and proved to be impermeable to carbon monoxide (CO). It is a 48% increase in the αH2/N2 permselectivity and fourfold increase in the αH2/CO2 permselectivity from bare PBI-HFA membrane. In this study, an effective Pd layer was deposited on PBI–HFA under optimum Pd electroless plating conditions by controlling the interface adhesion strength and distribution of Pd seeds on the substrate.
AB - Generally, Pd membranes used for H2purification are deposited on porous stainless steel (SS) or porous ceramics. These membranes are thick ( > 5 μm) because of the large pore size of the support used; hence, such thick membranes are not cost-effective. In this study, cost-effective, viable ultrathin Pd membranes, which were deposited on a polymer substrate, e.g., polybenzimidazole-4,4′-(hexafluoroisopropylidene)bis(benzoic acid) (PBI–HFA), with a thickness less than 700 nm, were prepared by vacuum electroless plating (VELP). The estimated thickness and effective permeation area of the Pd/PBI–HFA membranes were 130–656 nm and 8.3 cm2, respectively. An optimum Pd/PBI–HFA membrane was deposited after two times activation (A2). Because of the adequate grain size of Pd crystals and thickness, Pd/PBI–HFA exhibited better hydrogen permselectivity than the samples prepared by one and three times activation. Furthermore, the polymer surface treated by the CO2plasma (CO2) and oxidation by H2O2(H) leads to the enhanced selectivity performance of the final Pd/PBI–HFA membrane, caused by the enhanced adhesion between Pd and PBI–HFA. Gas permeation properties of H2, N2, CO2, and CO were evaluated between 35 and 200 °C and pressure differences between 4 and 8 bar. Pd films fabricated by A2-CO2methods exhibited superior performance, as well as excellent αH2/N2 and αH2/CO2 permselectivities of 41.4 and 22.3, respectively, at 150 °C and 8 bar, and proved to be impermeable to carbon monoxide (CO). It is a 48% increase in the αH2/N2 permselectivity and fourfold increase in the αH2/CO2 permselectivity from bare PBI-HFA membrane. In this study, an effective Pd layer was deposited on PBI–HFA under optimum Pd electroless plating conditions by controlling the interface adhesion strength and distribution of Pd seeds on the substrate.
KW - Activation
KW - Hydrogen separation
KW - Pd membrane
KW - Polybenzimidazole
KW - Vacuum electroless plating
UR - http://www.scopus.com/inward/record.url?scp=85013414455&partnerID=8YFLogxK
U2 - 10.1016/j.seppur.2017.02.033
DO - 10.1016/j.seppur.2017.02.033
M3 - Article
AN - SCOPUS:85013414455
VL - 179
SP - 486
EP - 493
JO - Separation and Purification Technology
JF - Separation and Purification Technology
SN - 1383-5866
ER -