Chemical,plasma chemical,and thermal modification of metallic catalysts

The role played by factors that modify the state of the surface of metals and their influence on catalytic activity are discussed. It is shown that the theoretical real gas model (two-dimensional electron gas-chemisorbed impurity particles) can be used to explain the character of the influence of nonmetallic and metallic impurities on the activity of catalysts. The influence of plasma chemical and thermal treatments of Rh, Ir, Ni, and Ag in the form of films, massive samples, and ultradisperse powders deposited on silica gel and Sibunite on their activity in the oxidation of CO, dehydrocyclization of n-C₆H₁₄, and dehydrogenation of isopropanol was studied. The influence of impurities and treatments specified was determined separately and in combination. The catalytic parameters changed because of changes in the surface electron density and the formation of structure defects on the surface of metals.