Improvement of the acidic properties of MOF by doped SnO quantum dots for the production of solketal

Metal-organic frameworks (MOFs) as acid catalysts provide active sites with particularly appropriate for glycerol conversion. In this study, Mil-118-SnO was synthesized by doping SnO quantum dots with Mil-118. The SnO quantum dots were formed through the epoxide-assisted precipitation route as a proton scavenger and following ring-opening that drives hydrolysis and, ultimately, condensation of the hydrated metal. The Mil-118-SnO was used as a catalyst for the production of five-member (2, 2-dimethyl-1, 3-dioxolane-4-methanol) and six-member (2,2-dimethyl-dioxane-5-ol, (II)) cycles. The results revealed a higher conversion rate and selectivity for Mil-118-SnO than for Mil-118. An increase was observed in conversion and selectivity, which was related to the improvement of the acidic properties of Mil-118 after doping SnO quantum dots. The experiments were conducted under mild conditions, producing a 40% increase in conversion and selectivity. This catalyst could be reused up to five times with 97% selectivity during a cycle. Graphical abstract: Glycerol is produced as the key byproduct in the transesterification process. The as-synthesized Mil-118-SnO then was used as a heterogeneous catalyst for the glycerol conversion to solketal. The experiments were carried out under mild conditions, which produced a 40% increase in conversion and selectivity.[Figure not available: see fulltext.].