In-Mg-hydrotalcite anionic clay as catalyst or catalyst precursor for Friedel-Crafts type benzylation reactions

Abstract

In-Mg-hydrotalcite (Mg/In = 3) anionic clay with or without calcination (at 200-800°C) or HCl pretreatment at different temperatures (26 and 80°C) and periods (0.1 or 1.0 h) has been used for the benzylation of benzene and/or substituted benzenes by benzyl chloride. The hydrotalcite before and after its calcination or HCl pretreatment was characterized for its surface area, crystalline phases and basicity. The hydrotalcite particularly after its use in the benzylation reaction, and the catalyst derived from it by its calcination at 800°C followed by HCl pretreatment (at 80°C for 1.0 h), shows high catalytic activity even for the benzylation of benzene. The catalytically active species present in the catalyst in its most active form are the chlorides and oxides of indium on the catalyst surface.