Sulfated Halloysite Nanoscrolls as Superacid Catalysts for Oligomerization of Hexene-1

Possibility of creating superacid catalysts on the basis of sulfated hydrosilicate nanoscrolls with halloysite structure and catalytic activity of the resulting materials in the model reaction of hexene-1 oligomerization were studied. The sulfation was performed with sulfuric acid solutions at concentrations of 0.25–1 M. The number of acid centers on the surface of the scrolls decreases with increase of the scid concentration, most probably due to the selective dissolution of the aluminum oxide sheet. In this case, the composition of the reaction products also changes, with the content of hexene-1 isomers increasing as compared with the oligomers. It was possible to obtain, at the lower boundary of the concentration range, an increased content of heavy fractions in the oligomerization products.