Abstract
Metallic membranes play important roles in membrane reactor technology for on-site hydrogen production application. Pd and Pd-25Ag alloy membranes with the thickness of 2.5 micro m were successfully prepared on silicon support using microfabrication technology in this work. Silicon-supported Pd alloy membranes were characterized by in-situ hydrogen microscope within the temperature range of 423 ~ 673 K. The Si-supported Pd-25Ag alloy membrane showed excellent resistance to hydrogen-induced brittleness whereas the Si-supported Pd membrane had fractured upon hydrogenation-dehydrogenation cycle. Ni-supported Pd membrane in 2.5 micro m thick was also successfully prepared for permeation characterization. Hydrogen permeation of the Ni-support Pd membrane was carried out in a conventional gas permeation apparatus using pure hydrogen and gas mixture of hydrogen and 28.3 Vol.% CO2, respectively. Grain growth had occurred in the Ni-supported thin Pd membrane during hydrogen permeation. Surface resistance was significant and increased with the addition of CO2.
