Alkylation of isobutene with 2-butene using composite ionic liquid catalysts Original Research Article

A composite ionic liquid was used as an acid catalyst for the liquid phase alkylation of isobutane and 2-butene. The main product obtained was trimethylpentane (>85 wt.%) and the research octane numbers of the alkylates was 98–101. In the ionic liquid sample, a composite anion [AlCl4CuCl]− was detected by means of ESI-MS. This new species was also confirmed by 27Al NMR and FT-IR characterizations. The effects of anion composition on the product distribution have been investigated. The composite anion plays important roles in improving alkylate quality.