A series of novel multi-functional heterogeneous catalysts was efficiently synthesized with the objective of creating a synergistic activation while unravelling the role of each single catalytic component. Spherical silica nanoparticles embedding Sn as single site (Sn-SiO₂) were prepared via a straightforward and time-saving procedure. The silica surface was selectively decorated with two different imidazolium-based moieties bearing primary or secondary alcohols in order to investigate if the presence of two co-catalysts (Lewis acid site and alcohol functionality) may induce a synergic activation improving the overall catalytic performances. The solids were fully characterized through ¹¹⁹Sn, ²⁹Si and ¹³C solid state NMR as well as via N₂-physisorption, transmission electron microscopy, ICP-OES and chemical combustion analysis. FT-IR of adsorbed CO₂ was employed to obtain some mechanistic insights on the interactions between CO₂ and the surface of the novel solids. All the synthesized catalysts were compared selecting the challenging CO₂ fixation on either cyclohexene oxide or styrene oxide to produce the corresponding cyclic carbonates. The best solids display excellent catalytic performances outcompeting with other totally heterogeneous catalysts previously reported in the literature. Finally, the true heterogeneous nature of the catalyst was proved in consecutive catalytic cycles. The characterization of the material after reuses allowed confirming the stability of the solid under the selected reaction conditions.

高效合成了一系列新型多功能非均相催化剂，目的是产生协同活化作用，同时揭示每个催化组分的作用。通过简单，省时的步骤制备了球形的纳米颗粒纳米颗粒，其内嵌有Sn作为单一位点（Sn-SiO ₂）。为了研究两种助催化剂（路易斯酸位和醇官能度）的存在是否会引起协同活化，从而改善整体催化性能，用两个带有伯醇或仲醇的咪唑基部分选择性地修饰了二氧化硅表面。通过¹¹⁹ Sn，²⁹ Si和¹³充分表征了固体C固态NMR以及通过N _2-物理吸附，透射电子显微镜，ICP-OES和化学燃烧分析。利用吸附的CO _2的FT-IR来获得一些有关CO ₂与新型固体表面之间相互作用的机理的见解。比较所有合成的催化剂，选择具有挑战性的CO ₂固定在环己烯氧化物或苯乙烯氧化物上，生成相应的环状碳酸酯。最好的固体表现出优异的催化性能，可与文献中先前报道的其他完全非均相催化剂相抗衡。最后，在连续的催化循环中证明了催化剂的真正多相性质。再利用后的材料表征可以确认固体在所选反应条件下的稳定性。