To deeply understand the role of surfactants on the acid/C4 hydrocarbon miscibility, the catalytic activity and molecular-level interfacial properties of long-alkyl-chain cationic surfactants (hexadecyltrimethylammonium bromide, CATB and dihexadecyldimethylammoniumchloride, DDAB) and anionic one (sodium dodecyl benzene sulfonate, SDBS) were studied as additives for H₂SO₄ alkylation using experiments and molecular dynamics simulations. Surfactant additives are found to efficiently decrease by-products and promote higher selectivity of trimethylpentanes (TMPs) and higher research octane number (RON), which is attributed to the improvement of acid/hydrocarbons interface, including better interfacial dispersion, higher I/O ratio, and lower interfacial tension. Surfactant additives show an interfacial intensification, quite different from intrinsic reaction intensification by low temperature. Combination of SDBS additive and lower temperature contributes to significantly higher TMP selectivity and higher RON up to 84.20 wt% and 99.07 at 269.2 K from 60.21 wt% and 94.34 at 281.2 K, respectively. The information provides good reference for the industrial H₂SO₄ alkylation.

中文翻译：

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长烷基链表面活性剂助剂促进低温下 H2SO4 催化的异丁烷烷基化

深入了解表面活性剂对长烷基链阳离子表面活性剂（十六烷基三甲基溴化铵，CATB和二十六烷基二甲基氯化铵，DDAB）和阴离子表面活性剂（十二烷基苯磺酸钠）的酸/C4烃混溶性、催化活性和分子级界面性质的作用, SDBS) 被研究作为 H ₂ SO _{4 的}添加剂使用实验和分子动力学模拟进行烷基化。发现表面活性剂添加剂可有效减少副产物并促进三甲基戊烷 (TMP) 的更高选择性和更高的研究辛烷值 (RON)，这归因于酸/烃界面的改善，包括更好的界面分散、更高的 I/O 比, 并降低界面张力。表面活性剂添加剂表现出界面强化，与低温引起的内在反应强化截然不同。SDBS 添加剂和较低温度的组合有助于显着提高 TMP 选择性和更高的 RON，分别从 60.21 wt% 和 281.2 K 时的 60.21 wt% 和 94.34 在 269.2 K 时达到 84.20 wt% 和 99.07。该信息为工业H ₂ SO ₄提供了很好的参考 烷基化。