Interaction of carbon monoxide with rhodium catalysts. Studies of adsorption and thermal desorption

The adsorption and temperature-programmed thermal desorption of carbon monoxide on rhodium catalysts has been investigated. Sequential adsorption/desorption cycles, with a maximum temperature of 573 K, result in the loss of ca. 71% of the catalysts original adsorptive capacity. At this stage a steady-state is reached and the desorption profile is identical to that obtained from a catalyst which had been used for carbon monoxide hydrogenation. Use of doubly labelled carbon monoxide revealed scrambled carbon monoxide was desorbed in the range 523–573 K. All carbon dioxide produced was formed by the water-gas shift reaction. An effect of both support and metal precursor was noted on the yield of carbon dioxide from this reaction.