“…27–30 Hopper et al found that the metal sulfates of Zr, Sn, Ti, and Cu also had suitable Brønsted acid sites for sorbitol dehydration, and isosorbide yields of 61% to 76% could be obtained. 31–35 According to these catalysts reported in previous papers, it can be seen that acidic resins, commercial resins, and self-prepared sulfonated polystyrene resins exhibited much higher activity, selectivity, and stability for sorbitol dehydration to isosorbide when compared to other heterogenous catalysts due to their high Brønsted acid strength and large quantity of sulfonate groups in aromatic rings.…”