In recent years, various kinds of heterogeneous acid catalysts have been prepared and utilized for different catalytic applications. Among them, designing the easily recoverable catalysts containing two distinct Brønsted acidic sites with enhanced catalytic properties is promising. In this work, modification of the mesopores of MCM-41 as a siliceous solid support with two suitable nitrogen-containing amino- and piperazine-propylsilyl groups followed by covalent interaction with 1,4-butane sultone introduced sulfonic acid groups to this mesoporous material. The additional electrostatic interaction with phosphotungstic acid groups generated the second acidic sites on ammonium and piperazinium moieties. The successful synthesis of these solid acid catalysts was confirmed by FT-IR, energy dispersive X-ray (EDX), and inductively coupled plasma optical emission (ICP-OES) spectroscopies; CHN elemental analysis; nitrogen sorption; and XRD techniques. The catalytic experiments in benzaldehyde acetalization with ethylene glycol resulted in moderate to high activity from 76% to 97% within 2 h. Moreover, the higher catalytic activity was related to the one possessing two kinds of acidic sites due to the synergistic effect between these acidic sites.

近年来，已经制备了各种多相酸催化剂并用于不同的催化应用。其中，设计包含两个不同的 Brønsted 酸性位点且具有增强催化性能的易于回收的催化剂是有前途的。在这项工作中，使用两个合适的含氮氨基和哌嗪丙基甲硅烷基对 MCM-41 作为硅质固体载体的介孔进行修饰，然后与 1,4-丁烷磺内酯共价相互作用，将磺酸基团引入到这种介孔材料中。与磷钨酸基团的额外静电相互作用在铵和哌嗪部分上产生了第二个酸性位点。FT-IR、能量色散 X 射线 (EDX) 证实了这些固体酸催化剂的成功合成，和电感耦合等离子体光发射 (ICP-OES) 光谱；CHN元素分析；氮吸附；和 XRD 技术。苯甲醛与乙二醇缩醛化的催化实验在 2 小时内产生了从 76% 到 97% 的中到高活性。此外，由于这些酸性位点之间的协同作用，较高的催化活性与具有两种酸性位点的一种有关。