Auger and Reaction Studies of Poisoning by Sulfur and Regeneration of Metal Synthesis Gas Catalysts. Progress Report, December 8, 1975--December 8, 1976 (open access)

Auger and Reaction Studies of Poisoning by Sulfur and Regeneration of Metal Synthesis Gas Catalysts. Progress Report, December 8, 1975--December 8, 1976

CO methanantion rates have been measured in the all-glass internal recycle reactor developed for this work. The methanation rate over the cylinder Ni film catalyst at 400/sup 0/C is 3.9 sec/sup -1/ initially, and the catalyst undergoes deactivation to a value of 1.8 sec/sup -1/, comparable with a reported value of 2.5 sec/sup -1/. The activation energy for Ni film on alumina is 24 kcal/mole, that for Ni film on silica is 17.8 kcal/mole comparable to values for Ni on these supports. The kinetics suggest that CO dissociation is rate limiting; carbon on the Ni is easily hydrogenated off. H/sub 2/S causes severe deactivation and regeneration after sulfur poisoning is not easily achieved by oxidation in the reactor. However, sulfur is easily removed from Ni by oxygen from a molecular leak in the high-vacuum chamber of the Auger electron spectrometer. Atmospheric pressure studies using an ante-chamber connected to the spectrometer chamber show that sulfur cannot be removed from Ni under conditions similar to those in the reactor because of rapid oxide growth which buries the sulfur preventing removal. Standards allowing determination of concentration as well as chemical state for Ni, O, S, and C have been developed.
Date: December 10, 1976
Creator: Katzer, James R.
System: The UNT Digital Library