Monodisperse composite microspheres were prepared of zirconia and urea formaldehyde resin having an average particle size of 2.2 μm. Their surface was modified by silane coupling agent and styrene, and then sulfuric acid assisted with silver sulfate to form solid sulfonic acid based ion-exchange catalyst (namely, ZrO₂-SIEC) for the alkylation of 2,4/2,5-xylenol mixture. The selectivities of catalyst ZrO₂-SIEC to produce 6-2,4-xylenol and 4-2,5-xylenol were found to be 98.9% and 97.9%, with yields of 98.6% and 80.9%, respectively. The optimized reaction conditions were identified including temperature (80°C), catalyst dosage (9%) and reaction time (180 min). In addition, catalyst ZrO₂-SIEC showed good reusability for maintaining stable catalytic performance over 25 cycles of reuse, attributed to its stable mechanical, thermal and chemical properties. Comparison with other four catalysts demonstrated good performance of ZrO₂-SIEC in terms of catalytic activity, operating conditions, separation from products, and environmental friendliness.

中文翻译：

---

一种环保且可重复使用的固体酸催化剂 ZrO2-SIEC，用于 2,4/2,5-二甲苯酚的高选择性烷基化

由氧化锆和脲醛树脂制备平均粒径为2.2 μm的单分散复合微球。它们的表面用硅烷偶联剂和苯乙烯改性，然后用硫酸辅助硫酸银形成固体磺酸基离子交换催化剂（即 ZrO ₂ -SIEC），用于 2,4/2,5-二甲苯酚的烷基化混合物。发现催化剂ZrO ₂ -SIEC生产6-2,4-二甲苯酚和4-2,5-二甲苯酚的选择性分别为98.9%和97.9%，产率分别为98.6%和80.9%。确定了优化的反应条件，包括温度（80°C）、催化剂用量（9%）和反应时间（180 分钟）。此外，催化剂 ZrO ₂-SIEC 表现出良好的可重复使用性，可在 25 次重复使用循环中保持稳定的催化性能，这归因于其稳定的机械、热和化学性能。与其他四种催化剂的比较表明，ZrO ₂ -SIEC 在催化活性、操作条件、与产物的分离和环境友好方面具有良好的性能。