Interaction of carbon monoxide with platinum/alumina and platinum/silica catalysts: 14C carbon monoxide tracer studies of adsorption, desorption, and catalyst poisoning

Abstract

The adsorption and temperature-programmed thermal desorption of ¹⁴C CO on Pt/Al₂O₃ and Pt/SiO₂ has been investigated. Amounts of CO adsorbed per g of Pt/Al₂O₃ and Pt/SiO₂ were (3.05 ± 0.11)× 10¹⁹ and (1.07 ± 0.08)× 10¹⁹ molecules respectively. A loosely bound state of CO was detected. Thermal desorption over the range 293 to 700 K revealed the desorption of CO₂ and CO. Ratios of CO₂ to CO were 7.07 and 0.70 for Pt/Al₂O₃ and Pt/SiO₂ respectively. Production of CO₂ was suppressed by the presence of adsorbed H₂S. The effect of adsorbed CO on the hydrogenation and hydriosomerisation of but-1-ene was also investigated. The results are discussed in terms of the nature of the adsorbed states of CO.