A Pd-MOS structure as a hydrogen sensor in catalytic reactions
1984 (English)In: Journal of Vacuum Science & Technology B, ISSN 1071-1023, E-ISSN 1520-8567, Vol. A2, 1032- p.Article in journal (Refereed) Published
By letting a catalytic reaction involving hydrogen occur on the Pd gate metal of a Pd–MOS structure the amount of hydrogen atoms on the surface can be monitored without any external probes by measuring the dipole induced by the hydrogen atoms that have diffused to the Pd–SiO2 interface. The ability to work over a wide pressure range (10-11 Torr to atm) makes the Pd–MOS structure an interesting device in the study of catalytic reactions. In this article, we will give a short review of some of the many applications of this component. We have combined this technique with other surface sensitive techniques such as UPS, XPS, work function measurements and mass spectrometry and, e.g., studied how the hydrogen adsorption–desorption processes are influenced by alloying the Pd surface with various amounts of Ag, thereby also changing the distribution of d states close to Fermi energy. We have also studied the H2+O→H2O reaction on Pd. It, e.g., turns out that the water reaction rate reaches a maximum when the oxygen coverage approaches zero and that the hydrogen atoms on the surface have a larger lateral mobility.
Place, publisher, year, edition, pages
1984. Vol. A2, 1032- p.
IdentifiersURN: urn:nbn:se:liu:diva-67244DOI: 10.1116/1.572667OAI: oai:DiVA.org:liu-67244DiVA: diva2:408711