Highly active organosulfonic aryl-silica nanoparticles as efficient catalysts for biomass derived biodiesel and fuel additives

Abstract

Post-grafting methodologies were used to prepare aryl-organosulfonic acid functionalized silica nanoparticles (SO 3 H-aryl-SiO 2 NPs) as highly active heterogeneous acid catalysts for catalytic esterification of free fatty acids (FFA) and levulinic acid (LA), and aldol condensation of furfural with 3-methylfuran, well known renewable feedstocks for biodiesel and fuel additives production. The chemical and structural characterization of the SO 3 Haryl-SiO 2 NPs confirmed the success of the functionalization. Complete conversion for all FFA was observed using SO 3 H-aryl-SiO 2 NPs after 2 h of reaction. SiO 2 NPs_CSPTMS showed to be the most active and stable catalyst with no significant loss of activity in the first 5 cycles. In the LA esterification in the presence of an alcohol, complete conversion and selectivity and high reusability were observed (e.g., 83.2% yield after 10 cycles in the presence of 1-propanol, SiO 2 NPs10_CSPTMS, at 120 • C and 2h reaction). Finally, aldol condensation of furfural and 3-methylfuran had been performed using SiO 2 NPs_CSPTMS catalysts with almost 100% yield after 10 min at 65 • C, high stability and reusability for 7 catalytic cycles.In general, the prepared SO 3 H-aryl-SiO 2 NPs have demonstrated promising catalytic performance for transformation of biomass-derived feedstocks into biodiesel and fuel additives.

Sulfonic Acid-Functionalized Inorganic Materials as Efficient Catalysts in Various Applications: A Minireview

“…Meanwhile peaks due to the presence of the organic groups arise with feature attributable to -CH stretching (2974-2893 cm −1 ) and to skeletal vibrations (1600-1400 cm −1 ). Moreover the SO 3 − symmetrical and asymmetrical vibrational modes (at 1046 and 1125 cm −1 ) arise above of the characteristic modes of the silica network (1165-1150 cm −1 ) [14,85,91]. The absence of peaks due to -SH functional groups (S-H stretching 2563 cm −1 ) is an indication of the efficiency of the oxidation step [86,92].…”

“…The acidity capacity in mmol g −1 is measured after letting the acid powder balance with a solution of NaCl used as cation exchanger. [88,91,101,102]. The direct titration with NaOH along with the reverse titration with HCl or H 2 SO 4 [103] gives accurate indication of the functionalization degree.…”

“…The comparison between the pyridine FT-IR and classical titration can provide information on the different types of Bronsted and Lewis acidities. For the evaluation of the functionalization degree a precise quantification of carbon, hydrogen and sulfur can be performed by elemental analysis by combustion of the organic moieties [14,15,91,101,104].…”

Interesterification of Glyceryl Trioctanoate Catalyzed by Sulfonic Silica-Based Materials: Insight into the Role of Catalysts on the Reaction Mechanism

“…After 6 h at 130 °C, the propyl-sulfonic catalyst gave 6% and 0% of triglyceride conversion and FAEE yield, respectively, whereas the phenyl-sulfonic catalyst gave 20% and 19%, respectively, using in both cases 1:20 triglyceride to ethyl acetate molar ratio and 13 wt% of catalyst. This kind of catalyst has been successfully investigated in many biodiesel-related acid-catalyzed processes [ 43 , 44 ] including esterification [ 13 ], transesterification [ 45 ], and acetylation [ 46 ]. Hybrid catalysts have the peculiarity of acting as “homogeneous supported” catalysts.…”

A Heterogeneous Bifunctional Carbon Nanocatalyst from Plastic Waste to Efficiently Catalyze Waste Cooking Oil into Biodiesel

“…An introduction of basic metal, such as Mg on the magnetic nanocatalyst core, Mg/Fe 2 O 3 -SiO, was effective for catalyzing Camelina sativa seed oil into biodiesel at 99% of yield within 4 h and maintaining the reactivity up to six reaction cycles [17]. A solid acid catalyst, SO 3 H-aryl-SiO 2 NPs, was synthesized via co-condensation method and successfully esterified FFA for five reaction cycles without leaching for every 2 h, with a yield above 82.3% [18]. Nevertheless, the catalyst 100% made up of metal NPs might be expensive for the production cost, which can be overcome by waste materials for its production.…”