The nopol rate model with ethyl acetate was the same that with toluene as solvent. Adsorption constants of compounds involved in the reaction were determined. Non-ideality of the liquid phase was related with the solvent solvation capacity. Solubility of formaldehyde in ethyl acetate was higher than in toluene.

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In this work, we investigate the influence of the Sn-loading and the pore size of MCM-41 materials on catalytic nopol production. Sn­(IV) was anchored onto MCM-41 by incipient wetness impregnation with metal coverages within 0.01 and 0.5 Sn nm–2 (i.e., below the monolayer content). We provide evidence that at coverages below 0.06 Sn nm–2, Sn­(IV) is predominantly present as isolated centers, whereas at higher coverages octahedral and/or oligomeric species are formed, which exhibit lower catalytic activity. The rate of nopol production over Sn/MCM-41 was ten times higher than that of analogous Sn silica gel materials. The turnover frequency features a maximum as a function of Sn coverage between 0.03 and 0.05 Sn nm–2 for Sn/MCM-41 catalysts and 0.15 Sn nm–2 for Sn silica gel materials. These results show that both the metal content and pore size can be tuned to enhance catalytic performance of Sn/MCM-41 materials.

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