ie8b03923_si_001.pdf (407.28 kB)
Understanding Structure–Property Relationship of SO3H‑Functionalized Ionic Liquids together with Sulfuric Acid in Catalyzing Isobutane Alkylation with C4 Olefin
journal contribution
posted on 2018-10-24, 00:00 authored by Weizhen Sun, Weizhong Zheng, Wenxiu Xie, Ling ZhaoIn this work, the SO3H-functionalized
ionic liquids
(SFILs) ([CnPSIm][HSO4], n = 1, 2, 4, 6, and 8) were investigated as cocatalyst mixed
with the concentrated H2SO4 for the isobutane
alkylation. The SFILs with longer alkyl chain show a better catalytic
performance with the C8 selectivity up to 75.73 and RON up to 95.66,
respectively. The better catalytic performance can be attributed to
the better dispersion of isobutane in the SFIL/H2SO4 system led by the SFILs with longer alkyl chain, which is
further correlated with the nanostructured-aggregation feature of
the longer alkyl chain confirmed by MD simulation. In addition, the
reusability of SFIL/H2SO4 mixture can reach
up to 22 runs, outclassing the pure H2SO4. The
MD simulation, quantum chemistry calculations, and 1H NMR
spectra revealed that cationic clusters are formed by the strong hydrogen
bonds between the sulfonic acid group and the H2SO4, which is beneficial to the longer lifetime of the SFIL/H2SO4 mixtures. Hopefully, the useful information
in this work will provide valuable insights into the screening and
design of novel SFILs for the H2SO4 alkylation.