Physical adsorption and chemisorption of hydrocarbons on a reduced alumina-chromia catalyst

Adsorption of ethane, butane, hexane, and benzene on a reduced alumina-chromia catalyst was investigated at 20–460 °C. The temperature ranges of physical adsorption and chemisorption were determined. The rate of hydrogen evolution is directly proportional to the rate of chemisorption of hydrocarbons. It was suggested that chemisorption of hydrocarbons results in the formation of intermediates in which Cr²⁺ ions and carbon atoms are linked by σ-bonds. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1375–1378, August, 2000.     

The adsorption of benzene and n-hexane on aluminum oxide

Summary Benzene is physically adsorbed on Al₂O₃ at 20–100° in greater amount than is n-hexane. In the range 100–150°, chemisorption of both hydrocarbons begins and decreases with increase in temperature.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 900–902, May, 1965 Original article submitted July 22, 1964     

Deactivation of reduced aluminum-chromium catalysts during heat treatments

Conclusions Depending on the heat treatment conditions, a parallelism was detected between the change in the amount of Cr²⁺ and the change in the yield of toluene from n-heptane on a reduced aluminum-chromium-potassium catalyst. One of the possible reasons for the heat deactivation of reduced aluminum-chromium-potassium catalysts is a decrease in the number of Cr²⁺ ions on their surface.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1644–1646, July, 1973.