Chemisorption of gases and reaction of propane dehydration at chromic oxide

Characteristics of Cr2O3 as an adsorbent and as a catalyst of propane dehydration by carbon dioxide are studied by adsorption and calorimetric techniques and by kinetic techniques, respectively. Carbon dioxide is usually applied as a dehydrating agent for a number of processes in the coal-chemical industry. For the first time, the molar heats of chemisorption of gases at Cr2O3 are studied under elevated temperatures. Cr2O3 surface is homogeneous relative to its chemisorption ability. Hydrogen is capable of chemisorbing at the surface (the molar heat of chemisorption is equal to 309.4 kJ/mol) and of sorbing into the solid body (the molar heat of sorption is equal to 170.45 kJ/mol), carbon dioxide is capable of chemisorbing at the surface (the molar heat of chemisorption is equal to 103 kJ/mol). The occurrence of hydrogen in the Cr2O3 body induces the Cr2O3 capability of sorbing an additional oxygen amount over that characteristic for completely oxidized samples that contain no hydrogen. Chemisorption of excessive oxygen proceeds up to the stoichiometry that corresponds to formation of hydroxyls in the Cr2O3 body. Hydrogen sorption by chromic oxide influences its catalytic activity.