Effects of palladium thin films on the hydrogen permeability of Pd-Cu alloy membranes

Al-Mufachi, Naser Azzat (2015). Effects of palladium thin films on the hydrogen permeability of Pd-Cu alloy membranes. University of Birmingham. Ph.D.

 Preview
Al-Mufachi15PhD.pdf
PDF - Accepted Version

Abstract

The hydrogen permeability of surface modified Pd$$_6$$$$_0$$ Cu$$_4$$$$_0$$ wt% (Pd$$_4$$$$_7$$$$.$$$$_3$$Cu$$_5$$$$_2$$$$_.$$$$_7$$at%) membranes have been determined for the first time. Surface modification was accomplished through the deposition of Pd thin films of three different thicknesses (95.5 ± 0.1, 797.4 ± 0.2 and 1,409.6 ± 0.2 nm) on to one side of a range of as-received Pd$$_6$$$$_0$$ Cu$$_4$$$$_0$$ wt% membrane coated with a 1,409.6 ± 0.2 nm thick Pd thin film positioned on the feed side (445 kPa of hydrogen pressure) and cycled between 50 and 450 °C achieved the highest hydrogen permeability of 1.09 x 10$$^-$$$$^8$$ mol m$$^-$$$$^1$$ s$$^-$$$$^1$$ Pa$$^-$$$$^0$$$$^.$$$$^5$$ at 450 °C during the third cycle. This is a 58% increase on the value measured for the as-received Pd$$_6$$$$_0$$ Cu$$_4$$$$_0$$ wt% under the same conditions.

This improvement can be attributed to a Pd-rich Pd-Cu face centred cubic (FCC) phase forming through
interdiffusion between the Pd thin film and bulk Pd-Cu membrane as a result of the test conditions used during hydrogen permeability measurements. This introduces a larger hydrogen concentration gradient across the membrane due to the relatively high hydrogen solubility of the Pd-rich Pd-Cu FCC phase resulting in the observed increase in permeability.

Type of Work: Thesis (Doctorates > Ph.D.)
Award Type: Doctorates > Ph.D.
Supervisor(s):
Supervisor(s)EmailORCID
Steinberger-Wilckens, RobertUNSPECIFIEDUNSPECIFIED
Rees, NeilUNSPECIFIEDUNSPECIFIED
Licence:
College/Faculty: Colleges (2008 onwards) > College of Engineering & Physical Sciences
School or Department: School of Chemical Engineering
Funders: Engineering and Physical Sciences Research Council
Subjects: T Technology > TP Chemical technology
URI: http://etheses.bham.ac.uk/id/eprint/6028

Actions

 Request a Correction View Item