A potential catalyst for α-pinene isomerization: a solid superacid

Abstract

A series of SO₄²⁻/TiO₂ solid superacid catalysts were prepared under different conditions. The effect of different preparation conditions on the SO₄²⁻/TiO₂ catalyst was investigated by evaluating the change of its crystallinity, chemical structure and acid content. The catalytic performance of the SO₄²⁻/TiO₂ catalyst was evaluated by α-pinene isomerization in a continuous fixed bed reactor. When ammonia was used as the precipitation agent, the concentration of sulfuric acid impregnation solution was 2 M, and the calcination temperature was 500 °C, the activity of the SO₄²⁻/TiO₂ catalyst reached the maximum, the conversion rate of α-pinene was stable at about 95%, and the selectivity of camphene reached 40%. It was found that the structure and textural properties of the SO₄²⁻/TiO₂ catalyst did not change significantly after regeneration by studying the regeneration performance of the SO₄²⁻/TiO₂ catalyst.