Propyl-SO3H functionalized graphene oxide as multipurpose solid acid catalyst for biodiesel synthesis and acid-catalyzed esterification and acetalization reactions
Graphical abstract
Introduction
Esterification of carboxylic acids with alcohols has attracted much attention for industrial manufacturing valuable chemicals such as solvents, fragrances, polymers, biodiesel, etc. in recent years [1]. Because of the increase in energy consumption and considering the depletion of non-renewable fossil fuels in future, biodiesel has been found to be a good alternative in industry. Biodiesel is sustainable, renewable, clean, and sulfur-free fuel composed of fatty acid monoalkyl esters, mainly produced via esterification of fatty acids or trans-esterification of triglycerides available in edible or non-edible oils with short-chain primary alcohols using acid or base catalysts [[2], [3], [4], [5]]. However, it is important to esterificate free fatty acids such as oleic acid, linoleic acid, palmitic acid etc. in incompatible feedstocks prior to use base catalysts for transesterification reaction due to the soap formation. Hence, acid-catalysis is more appropriate for biodiesel production [6,7].
On the other hand, acid-catalyzed acetal formation is one of the most important steps in protecting carbonyl groups of aldehydes or ketones with various alcohols or diols in multistep organic syntheses for manufacturing fine chemicals [[8], [9], [10]]. Typically, mineral acids such as H2SO4, H3PO4, and p-toluene sulfonic acid are exploited as homogeneous catalysts to promote the productivity of esterification and acetalization reactions [1,11]. Despite the high efficiency of homogeneous catalytic processes, they suffer from some drawbacks such as difficult separation and recycling of catalyst, severe corrosion, and large production of waste arising from neutralization processes. In order to eliminate these problems for moving toward clean processes, insoluble solid acid catalysts are considered as suitable alternatives in organic transformations due to their facile separation, reusability, non-toxic property, and corrosion elimination as well as waste decrement [12,13].
Scientific researches on designing catalysts with specific morphological and textural properties has grown dramatically over the last few decades. The structural properties mainly affect the catalytic activity which in turn is relevant to the number of active sites and their availability for reactant molecules [[14], [15], [16], [17]]. Solid carbon materials e.g. activated carbon, carbon nanotube, fullerene, and graphene have been used as efficient supports to immobilize catalytically active components which consequently leads to promote the selective formation of desired products [[18], [19], [20], [21], [22]]. Graphene oxide (GO) containing a lot of oxygen functional groups has been utilized to prepare graphene based acid catalysts. To date, the most utilized reagents for sulfonation of the graphene nanosheets are sulfuric acid [[23], [24], [25], [26], [27], [28], [29], [30]], fuming sulfuric acid [31,32], chlorosulfonic acid [27,[33], [34], [35], [36], [37], [38]], and diazonium salt of sulfanilic acid [34,[39], [40], [41], [42], [43], [44], [45], [46], [47], [48], [49], [50], [51], [52]]. There are some reports on using graphene based solid acid catalysts in acid-catalyzed reactions. For example, Zhang et al. [23] prepared GO supported dual sulfonic/carboxylic acids to catalyze oleic acid esterification with methanol for biodiesel synthesis. In another work conducted by Liu et al. [31], sulfated graphene was hydrothermally synthesized by using fuming sulfuric acid and exploited as acid catalyst for acetic acid esterification with cyclohexanol and 1-butanol, Pechmann reaction of resorcinol with ethyl acetoacetate and hydration of propylene oxide. Moreover, the use of chlorosulfonic acid as sulfonation reagent was reported by Wei et al. [36] to synthesis sulfonated graphene oxide as a solid acid catalyst in hydrolysis of cellobiose, hydrolysis of isoflavone glycoside, and acetic acid esterification with ethanol. Oger et al. [47] and Zhang et al. [48] prepared graphene supported aryl sulfonic acid with using diazonium salt of sulfanilic acid for acid-catalyzed acetalization of carbonyl compounds with glycerol and additive esterification of carboxylic acids with olefins, respectively.
Despite the several use of graphene based acid catalysts in various organic reactions, the use of immobilized propyl sulfonic acid on the surface of graphene oxide (GO-PrSO3H) is only limited to catalyze the synthesis of star-shape phenolic compounds [53], and bisphenolic antioxidants [27]. To best of our knowledge, there is no any report on utilizing GO-PrSO3H acid catalyst in the esterification and acetalization reactions. In this research, we aim to prepare and fully characterize propyl sulfonic acid functionalized graphene oxide and examine its catalytic activity in acetic acid esterification with n-butanol, biodiesel synthesis through the oleic acid esterification with methanol, and benzaldehyde acetalization with ethylene glycol. This solid acid catalyst exhibited good catalytic performance compared with some other solid acid catalysts reported earlier.
Section snippets
Synthesis of propyl sulfonic acid functionalized graphene oxide (GO-PrSO3H)
Graphene oxide (GO) was synthesized with modified hummers method [54]. Surface silylation of GO was done by reacting excess amount of (3-mercaptopropyl) trimethoxysilane (5 mmol, 1 g) with 1 g of ultrasonically dispersed GO in dry toluene (30 ml). The mixture was refluxed for 24 h under N2 atmosphere. The obtained GO-PrSH was isolated by centrifugation, soxhlet washed with chloroform, and dried in vacuum oven at 70 °C overnight. In order to convert the –SH groups to –SO3H acidic sites, the
Preparation and characterization of GO-PrSO3H
Taking into account the fact that the surface of GO is rich in hydroxyl groups, it is known as a suitable support for incorporating various active species via surface post modification. The procedure used for preparing the GO based acid catalyst was shown in Fig. 1. At first, (3-mercaptopropyl) trimethoxysilane was selected as silylating reagent containing thiol group. The reaction was performed in dry toluene to prevent the possible side reaction of coupling the silyl groups together by
Conclusion
In summary, introducing propyl sulfonic acid groups as active acidic sites on the surface of graphene oxide (GO) produced a graphene based acid catalyst (GO-PrSO3H) with high surface acidity. Graphene oxide was selected as a proper solid support due to its high surface area (249 m2/g) and bearing several hydroxyl functional groups appropriate for surface post modification. The existence of covalently bound propyl-SO3H groups on the surface of GO was corroborated by FT-IR spectroscopy and EDX
Author contribution statement
Majid Masteri-Farahani: Supervision and corresponding author.
Mahdiyeh-Sadat Hosseini: Investigation and writing.
Newsha Forouzeshfar: Investigation and data collection.
Declaration of competing interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgements
The authors gratefully acknowledge financial support from the Iran National Science Foundation (INSF) [Grant No. 96006456].
References (79)
- et al.
Manufacturing of zeolite based catalyst from zeolite tuft for biodiesel production from waste sunflower oil
Renew. Energy
(2016) - et al.
Esterification of oleic acid to biodiesel catalyzed by a highly acidic carbonaceous catalyst
Catal. Today
(2019) - et al.
Transition-metal incorporated heteropolyacid-ionic liquid composite catalysts with tunable Brønsted/Lewis acidity for acetalization of benzaldehyde with ethylene glycol
Appl. Catal. Gen.
(2017) - et al.
Acetalization of carbonyl compounds catalyzed by acidic ionic liquid immobilized on silica gel
J. Mol. Catal. A Chem.
(2011) - et al.
Translation of lignocellulosic waste to mesoporous solid acid catalyst and its efficacy in esterification of volatile fatty acid
Microporous Mesoporous Mater.
(2018) - et al.
Solid acids: green alternatives for acid catalysis
Catal. Today
(2014) - et al.
Facile preparation of mesoporous TiO2 (B) nanowires with well-dispersed Fe2O3 nanoparticles and their photochemical catalytic behavior
Appl. Catal. B Environ.
(2014) - et al.
Sulfonated reduced graphene oxide (RGO-SO3H): as an efficient nanocatalyst for one-pot synthesis of 2-Amino-3-cyano-7-hydroxy-4H-chromenes derivatives in water
Polycycl. Aromat. Compd.
(2018) - et al.
Synthesis of potential antioxidants by synergy of ultrasound and acidic graphene nanosheets as catalyst in water
Int. J. Biol. Macromol.
(2016) - et al.
Synthesis and antioxidant activity of star-shape phenolic antioxidants catalyzed by acidic nanocatalyst based on reduced graphene oxide
Mater. Sci. Eng. C
(2017)
Conversion of lipids from wet microalgae into biodiesel using sulfonated graphene oxide catalysts
Bioresour. Technol.
Sulfonated graphene oxide as highly efficient catalyst for glycosylation
J. Carbohydr. Chem.
Biodiesel production from palm oil using sulfonated graphene catalyst
Renew. Energy
Carbocatalytic dehydration of xylose to furfural in water
Carbon
Sulfonated reduced graphene oxide as a highly efficient catalyst for direct amidation of carboxylic acids with amines using ultrasonic irradiation
Ultrason. Sonochem.
Sulfonated graphene oxide-catalyzed N-acetylation of amines with acetonitrile under sonication
J. Taiwan Inst. Chem. Eng.
Clicked graphene oxide supported venturello catalyst: a new hybrid nanomaterial as catalyst for the selective epoxidation of olefins
Mater. Chem. Phys.
Clicked graphene oxide as new support for the immobilization of peroxophosphotungstate: efficient catalysts for the epoxidation of olefins
Colloids Surf., A
Synthesis and sulfation of titanium based metal organic framework; MIL-125 and usage as catalyst in esterification reactions
Catal. Commun.
The synthesis of heterogeneous 7-amino-1-naphthalene sulfonic acid immobilized silica nano particles and its catalytic activity
J. Taiwan Inst. Chem. Eng.
The hydrophilic/hydrophobic effect of porous solid acid catalysts on mixed liquid phase reaction of esterification
Catal. Commun.
Activated clay supported heteropoly acid catalysts for esterification of acetic acid with butanol
Appl. Clay Sci.
Synthesis of lacunary polyoxometalate encapsulated into hexagonal mesoporous silica and their catalytic performance in esterification
Microporous Mesoporous Mater.
Preparation of magnetic nanocomposites of solid acid catalysts and their applicability in esterification
Chin. J. Catal.
A highly efficient catalyst for the esterification of acetic acid using n-butyl alcohol
J. Mol. Catal.
Acidic ionic liquid-catalyzed esterification of oleic acid for biodiesel synthesis, Chin
J. Catal.
Kinetic study of oleic acid esterification over 12-tungstophosphoric acid catalyst anchored to different mesoporous silica supports
Fuel Process. Technol.
Preparation of sulfonated ordered mesoporous carbon and its use for the esterification of fatty acids
Catal. Today
Application of glucose derived magnetic solid acid for etherification of 5-HMF to 5-EMF, dehydration of sorbitol to isosorbide, and esterification of fatty acids
Tetrahedron Lett.
One-pot fabrication of magnetically recoverable acid nanocatalyst, heteropolyacids/chitosan/Fe3O4, and its catalytic performance
Appl. Catal. Gen.
Influence of alkyl chain length on sulfated zirconia catalysed batch and continuous esterification of carboxylic acids by light alcohols
Green Chem.
Advancements in solid acid catalysts for biodiesel production
Green Chem.
Heterogeneous catalysis for sustainable biodiesel production via esterification and transesterification
Chem. Soc. Rev.
Preparation of ethane-bridged organosilica group and keggin type heteropoly acid co-functionalized ZrO2 hybrid catalyst for biodiesel synthesis from eruca sativa gars oil
Catal. Sci. Technol.
Monodispersed hollow SO3H-functionalized carbon/silica as efficient solid acid catalyst for esterification of oleic acid
ACS Appl. Mater. Interfaces
Synthesis of sulfonic acid-functionalized Fe 3 O 4@ C nanoparticles as magnetically recyclable solid acid catalysts for acetalization reaction
Dalton Trans.
Sulfonic acid functionalized silica nanoparticles as catalysts for the esterification of linoleic acid
New J. Chem.
Heteropoly acid and ZrO 2 bifunctionalized organosilica hollow nanospheres for esterification and transesterification
J. Mater. Chem. A
Antisolvent precipitation for the synthesis of monodisperse mesoporous niobium oxide spheres as highly effective solid acid catalysts
ChemCatChem
Cited by (49)
Photocatalytic esterification of acetic acid with methanol over metal-exchanged phosphotungstate
2024, Journal of Photochemistry and Photobiology A: ChemistryRecent developments in solid acid catalysts for biodiesel production
2023, Molecular CatalysisGraphene-based catalysts for biodiesel production: Characteristics and performance
2023, Science of the Total EnvironmentCitation Excerpt :It is usually possible to separate graphene-based catalysts from a system by filtration, centrifugation, or by creating a magnetic field (if magnetic nanoparticles are present). Conversely, despite their high efficiency, catalysts such as ionic liquids require a process with high energy consumption for separation due to their homogeneous structure and very high boiling point (Masteri-Farahani et al., 2020). Graphite as a raw material for the synthesis of graphene-based compounds is very cheap.