Catalytic isomerisation of but-1-ene to 2-methylpropene over solid acids: comparison between DAF-1 and other shape-selective magnesium-containing aluminophosphates and aluminosilicates

Although DAF-1 is a superior isomerisation catalyst at lower temperatures [reaching some 50% of the thermodynamically limited conversion in the range 250–300°C at a weight hourly space velocity (WHSV) of but-1-ene of 3 h–1] both its activity and its selectivity, as well as its longevity, are inferior to those of H+-ferrierite and H+-Theta-1 in the range 350–400°C: the performance of MALPO-5, -11 and of –36 (M = Mg) is much poorer than that of DAF-1.