UHV-compatible reaction cell for combined high- and low-pressure studies of surface reactions

Abstract

The construction and performance of a combined reaction cell and sample exchange lock for studies of surface reactions at pressures up to a few atmospheres is described. In combination with a specially designed sample holder this construction allows simple and rapid transfer of the sample betwen the ultrahigh vacuum system and the reaction cell. The reaction cell is a self-contained unit that can be mounted on, e.g., a 2 3/4 -in. Con-Flat flange (or any other vacuum port with an I.D.≥38 mm). The sample holder can be mounted on any commerical sample manipulator. In both the high- and low-pressure positions the sample can be heated and cooled. Results are presented for the times involved in moving the sample from high- to low-pressure environments, pump-out times, etc. The use of this equipment in studies of the catalytic activity of Pt for the H2 oxidation is briefly described.