TEXTURE, STRUCTURE, AND SURFACE AND CATALYTIC PROPERTIES OF SILICA-GEL THAT HAS BEEN MODIFIED BY CHEMICAL MIXING .3. IR SPECTROSCOPIC AND CATALYTIC STUDY OF MODIFIED SIO2

For a comparison of the acidic and catalytic properties of SiO2 doped with Al3+, Ti4+, or Zr4+ cations, the adsorption of pyridine has been investigated by means of IR spectroscopy, and the oligomerization of isobutylene has been studied in a flow system. Both Lewis and Bronsted centers were present on the surface of all of the catalysts, but the greatest quantity of the Bronsted centers was found on the Al2O3-SiO2 samples, which also proved to be the most active in the oligomerization reaction.