Palladium, yttrium, copper ternary alloys for hydrogen purification

Palladium has long been recognised for its hydrogen sorption and separation capabilities. Alloying with different metals to produce binary alloys has been shown to further improve many of its essential properties significantly. Currently palladium-silver alloys are used commercially for the hydrogen purification process, however, other binary alloys have also been shown to significantly improve the hydrogen sorption properties (palladium-yttrium), and palladium’s resistance to poisoning by hydrogen sulphide (palladium-copper). Whilst a number of binary palladium alloys have previously been investigated none has shown all the required target properties for an effective hydrogen purification membrane as set by the US DoE. This work will study a number of palladium, yttrium, copper, ternary alloys of varying copper compositions, and investigate their characteristics as a suitable hydrogen purification material. The produced membranes, will be characterised using X-ray diffraction, scanning electron microscopy, hardness measurements, and the use of a confocal microscope and then tested using a hydrogen flow rig, to determine their suitability as a hydrogen purification material. Results showed that the addition of a small amount of copper to a Pd-8at%Y alloy leads to marked changes in a number of key alloy parameters relevant to membrane performance. The lattice parameter was increased, as was hydrogen flow, and materials hardness, whilst average grain size was reduced.

Name dc:type.qualificationname

m_rs

Level dc:type.qualificationlevel

m_rs

Grantor dc:publisher.institution

University of Birmingham

Year dc:date.issued

2010

Author dc:creator

• Grant, Joanne Louise

• TD Environmental technology. Sanitary engineering