A VERSATILE INFRARED CELL FOR IN-SITU CATALYST PRETREATMENT AND MEASUREMENTS AT TEMPERATURES BETWEEN 120 AND 773 K - APPLICATION TO ALUMINA-SUPPORTED NIO AND WO3

A new infrared (IR) transmission cell has been developed which allows in situ catalyst pretreatment under well-controlled conditions, follow ed by the characterization with IR spectroscopy on adsorbed CO at 120 K. The temperature of the sample can be controlled accurately from 120 up to 773 K while the sample is present in the IR beam. In an integra ted reactor, the sample can be heated from 300 up to 1273 K under reac tive conditions, for instance in H2S. To ease the comparison of differ ent samples pretreated under identical conditions, for instance for ba ckground corrections, the sample holder may contain two samples. The t ransmission cell is high vacuum compatible and has been built in a tra nsportable frame allowing a flexible use of the IR spectrometer. The p erformance of the cell is demonstrated for the characterization of an oxidic Ni/Al2O3 sample and a reduced WO3/Al2O3 sample. (C) 1998 Elsevi er Science B.V. All rights reserved.