Mesoporous Solid Acid Catalysts Research Articles

Catalytic dehydration of fructose to 5-hydroxymethylfurfural over mesoporous Nb-W oxide solid acid catalyst

In this study, a mesoporous Nb-W oxide solid acid catalyst was synthesized and characterized in detail by TEM, N2 physisorption, and Py-FTIR. Effects of the calcination temperature on the pore structure and acid properties were investigated. The results showed that increasing calcination temperature from 400 °C to 600 °C remarkably affected the characteristics of mesoporous Nb-W oxides, with a decrease in specific surface area, pore volume, and acid amount, but an increase in pore size from 5.1 nm to 10.4 nm. Furthermore, a notable decrease was found in both the fructose conversion and HMF yield in the dehydration of fructose to HMF over Nb-W oxides when increasing the calcination temperature, and the catalyst could keep high catalytic activity and selectivity after recycling 4 times. Solvents also played a key role in the fructose dehydration to HMF over the Nb-W oxides, and DMSO was the optimized solvent. 1H NMR and 13C NMR experiments revealed that the key intermediate, 4-hydroxy-5-hydroxymethyl-4,5-dihydrofuran-2-carbaldehyde, could generate in DMSO but not in other solvents including NMP, DMF, DMAC, and EG.

Synthesis, Characterisation and Catalytic Evaluation of Castor Oil-Templated Mesoporous Sulfated Solid Acid Catalysts for Esterification Reaction

In bio-refinery and other catalytic reactions, heterogeneous catalysts confer advantage over homogenous catalysts due to minimized recovery and separation costs. However, templating surfactant and solid support for the synthesis of heterogeneous catalysts ought to consider their cheap sources and environmentally friendliness for their sustainable use. Thus, with the vision to make the process significantly benign, in the present work, solid acids were synthesised from renewable sources (castor oil as surfactant and rice husk as the source of silica). The synthesised castor oil-templated mesoporous sulfonic acid modified catalysts (SO3H-MTS and SO3H-MT-RHS) were characterised and evaluated for catalytic esterification of acetic acid (C2), hexanoic acid (C6), lauric acid (C12), palmitic acid (C16), and ricinoleic acid (C18) with butanol at 110 °C. Physicochemical properties of the synthesised materials were characterised by nitrogen porosimetry, X-ray powder diffraction, thermogravimetry, X-ray Photoelectron Spectroscopy (XPS), and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). The porosimetric analysis of the synthesised materials revealed a type IV adsorption-desorption isotherm reminiscent of the mesoporous structures. The surface area of the synthesised materials decreased upon functionalisation by sulfonic group. The DRIFTS and XPS confirmed the attachment of sulfonic functional group on the synthesised materials. Evaluation of the catalytic performance of the synthesized materials was determined through analysis of carboxylic acid conversions using gas chromatographic technique. SO3H-MTS gave higher acid conversions compared to SO3H-MT-RHS. The sulfated solid acid catalysts showed good catalytic activity on the esterification with conversion ranging from 96-37% for C2-C18 with butanol at 110 °C within 6 h. Such castor oil-templated mesoporous sulphated solid acid catalysts can therefore be applied in biodiesel production upon process optimisation.

Efficient removal of acetaldehyde from ethanol by template-free synthesized mesoporous SiO2-based solid acid catalyst with high surface silicon exposure

In the absence of any template, mesoporous silica-based solid acid owing a high surface area (380.2 m2/g), big average pore size (5.6 nm), and moderate acid amount (1.33 mmol/g) was synthesized through a one-step reverse-phase microemulsion method. The introduction of 3-sulfopropyl as the acidic sites by this method increased the surface silicon exposure to a high value of 74.1 %, which enabled plenty of active groups to be available on the surface. As the main impurity in ethanol and has the potential to cause the serious damage for people’s health, acetaldehyde was removed with high removal (above 99.99 %) from ethanol through a novel strategy of “waste to value” with the present acid catalyst at the ambient temperature, in which acetaldehyde was converted to a much safer chemical of acetal that owns a pleasant odor and is permitted to be used as the fragrance in food. The remaining acetaldehyde could be controlled to a very low and much safer level of below 0.01 ppm with a wide range of initial concentration.

Efficiently and directly produce triacetylglycerol from oils and fats over mesoporous polymeric solid acid catalysts

A series of mesoporous solid acid catalysts (PDS-x) with large BET surface area, superior thermal stability, strong sulfonic acid groups and tunable Brønsted acidity were synthesized by the copolymerization of divinylbenzene (DVB) and sodium p-styrenesulfonate (SPSS). The PDS-x catalysts showed high activity on the direct and efficient production of triacetylglycerol (TAG) via acyl exchange reaction of oils (fats) and acetic acid. The highest TAG yield of 93.0 mol% was obtained on the PDS-x catalysts at a mild condition of 200 °C. By combining SEM, TEM, FT-IR/DRIFTS, BET, XRD, XPS, EA, 31P MAS NMR and TG-DTG, the key factors that affected the TAG yield were clarified on the PDS-x catalysts. Moreover, the origin of the slow deactivation on these catalysts was elucidated. The large BET surface area and abundant mesopores of catalysts allowed the contact of large-sized oils (fats) with the strong sulfonic acid groups, accounting for the high TAG yield.

Mesoporous solid acid catalysts esterifying waste cooking oil to biodiesel at room temperature

This work presented the preparation and characterization of mesoporous AlPO4 and AlSiO4 by the sol-gel method with the help of isopropylamine as a template. Isopropylamine is a microporous template and it creates only 0–2 nm pores but in the present study, the same template creates mesoporosity in AlPO4 and AlSiO4. The synthesized material properties are characterized by XRD, IR, TGA, BET, TPD, SEM-EDX and HR-TEM. The results confirmed that the synthesized materials are crystalline, tetrahedral framework, thermal stability (800 °C), mesoporosity of AlPO4 (9 nm) and AlSiO4 (7 nm), the acidity of AlPO4 is 0.53 mmol/g and AlSiO4 is 1.16 mmol/g and it exhibits crystalline morphology. Catalytic activities are verified by biodiesel synthesis from waste cooking oil (WCO) as a low-cost feedstock by transesterification reaction. It was identified that the maximum selectivity of biodiesel over AlPO4 and AlSiO4 (89 and 96%) was achieved at room temperature. These catalysts are active at room temperature may be due to their porous nature. The results revealed that AlSiO4 is a more effective catalyst to synthesize biodiesel than AlPO4. These catalysts are environmentally friendly and reusable with the same efficiency.

Efficient conversion of glucose into 5-HMF catalyzed by lignin-derived mesoporous carbon solid acid in a biphasic system

A lignin-derived mesoporous carbon solid acid (LDMCS) catalyst was prepared by high temperature carbonization and subsequent sulfonation treatment using alkali lignin as the carbon source and KCl as a salt template. The prepared LDMCS has an irregular mesoporous structure with a narrow pore size distribution (concentrated at 4 nm), large specific surface area (1123.0 m2 g−1) and high -SO3H group density (2.20 mmol g−1). Compared with other types of solid acids reported in the literature, the prepared LDMCS catalyst has equivalent or better catalytic performance in the catalytic conversion of glucose to 5-hydroxymethylfurfural (5-HMF). A glucose conversion of 97.7% and a 5-HMF yield of 57.8% were obtained with the aqNaCl-THF (1:3) biphasic solvent system under the optimized reaction conditions with reaction temperature of 160 °C, reaction time of 2.5 h, and catalyst loading of 1 mg mg−1. More importantly, the 5-HMF yield still reached 40.9% after 5 cycles of the catalyst use, indicating that there was no significant loss of catalytic activity.

Efficient dehydration of fructose into 5-HMF using a weakly-acidic catalyst prepared from a lignin-derived mesoporous carbon

A lignin-derived mesoporous carbon solid acid catalyst (LDMCC) was prepared using alkali lignin as a carbon source and KCl as a salt template to generate a carbon support that was carboxylated with acrylic acid. The prepared LDMCCs were characterized by various spectroscopies (FTIR, XPS, XRD, Raman), porosity determinations (BET), microscopies (SEM, TEM), thermogravimetric analysis, and acid-base titration. The LDMCC produced at the highest carbonization temperature (900 °C) possesses a rich porous structure, high specific surface area (1197.1 m2·g−1), large pore volume (0.63 cm3·g−1), and abundant –COOH groups (2.4 mmol·g−1). This weakly acidic catalyst exhibits excellent synergistic catalytic performance with DMSO in the catalytic dehydration of fructose to prepare 5-hydroxymethylfurfural (5-HMF); the yield of 5-HMF was 96.0% using dimethyl sulfoxide as the solvent, reaction conditions of 180 °C for 2.0 h, and a catalyst loading of 0.1 mg·mg−1. In addition, the prepared LDMCC exhibits excellent reusability over five cycles of use without significant loss in its catalytic activity. This study provides a novel green route for the preparation of a weakly acidic catalyst which may be useful for a variety of biomass conversion processes.

SYNERGISM OF MUICAT-1 AND MICROWAVE IRRADIATION IN CLAISEN-SCHMIDT CONDENSATION OF BENZALDEHYDE WITH ACETOPHENONE TO CHALCONE

SYNERGISM OF MUICAT-1 AND MICROWAVE IRRADIATION IN CLAISEN-SCHMIDT CONDENSATION OF BENZALDEHYDE WITH ACETOPHENONE TO CHALCONE

Preparation and characterization of mesoporous polymer-based solid acid catalysts for biodiesel production via transesterification of palmitic oils

The hydrophobic and spherical PDVB-x-MeCN (x: molar ratio of p-styrene sulfonate/divinylbenzene; x = 0.0, 0.1, 0.3, 0.5, and 1.0) catalyst was synthesized via polymerization and the ion-exchange process. Moreover, the hydrophobic property of PDVB-x-MeCN with high contact angles (> 124.0∘) was directly observed with a contact angle analyzer. The most appropriate x value of PDVB-x-MeCN for free fatty acid (FFA) removal and biodiesel production was 0.5, which was identified with gas chromatography (GC). During a 6-h transesterification-esterification, FFA removal and biodiesel yield of PDVB-0.5-MeCN reached 83.2% and 83.3%, respectively, at a ratio 45/1 (v/v) of methanol/palmitic acid mixture, approaching that of the Amberlyst 15 ones (83.4%). On the basis of these results, waste oils containing FFA can be transesterified efficiently from triglycerides and FFA into biodiesel.

Silicotungstic acid-derived WO3 composited with ZrO2 supported on SBA-15 as a highly efficient mesoporous solid acid catalyst for the alkenylation of p-xylene with phenylacetylene

Highly dispersed silicotungstic acid-derived WO3 composited with ZrO2 supported on SBA-15 (WZ/SBA-15) as an ordered mesoporous solid acid catalyst was prepared via a facile incipient wetness impregnation (IWI) method that active ingredients, ZrO2 and WO3, were impregnated into the channels of SBA-15 simultaneously with a subsequent calcination process. The relationship between catalyst nature and performance was explored by high resolution transmission electron microscopy (HRTEM), high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), FT-IR, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), N2 adsorption-desorption, NH3 temperature-programmed desorption (NH3-TPD), and FT-IR of pyridine adsorption (Py-IR) characterization techniques. The catalytic performance of W12Z15/SBA-15 is not only greater than that of single component solid acid catalysts, WO3/SBA-15 and ZrO2/SBA-15, but also W12/Z15/SBA-15 prepared by impregnating active ingredients, ZrO2 and WO3, into SBA-15 in sequence. The outstanding performance of W12Z15/SBA-15 is derived from the strong interaction between ZrO2 and WO3, which results in more acid sites, and relatively high specific surface area, large pore volume, and ordered mesoporous structure of SBA-15. The characterization and reaction results clearly demonstrate that the synergy of ZrO2 and WO3 has a clear boost for the alkenylation. The optimized W12Z15/SBA-15-500 achieves a 99.4% conversion of phenylacetylene and a 92.3% selectivity of main product α-arylstyrene for the alkenylation of p-xylene with phenylacetylene, with very low level of oligomers producing at the same time. Moreover, W12Z15/SBA-15-500 shows excellent catalytic stability and regeneration. Therefore, W12Z15/SBA-15-500 is a promising solid acid catalyst for the alkenylation.

High-performance magnetite nanoparticles catalyst for biodiesel production: Immobilization of 12-tungstophosphoric acid on SBA-15 works effectively

Magnetic mesoporous solid acid catalysts, designed as Fe3O4@SBA-15@HPW and Fe3O4@SBA-15-NH2-HPW, were prepared for the production of biodiesel by the transesterification of palm oil with methanol. The magnetic mesoporous carrier was modified by two different methods: post-gifting method and impregnation method. The structure of the catalysts was characterized by SEM, TEM, XRD, FT-IR, VSM, Pyridine-FT-IR, N2 adsorption-desorption and TGA. The results indicated that they all had ordered mesoporous and excellent paramagnetic. Both Fe3O4@SBA-15@HPW and Fe3O4@SBA-15-NH2-HPW had high content of Brønsted acid sites due to the loading of 12-tungstophosphoric acid, which made the two catalysts very active. Particularly, Fe3O4@SBA-15-NH2-HPW was very efficient in the transesterification of palm oil with methanol and gave a more than 91% biodiesel yield when the reaction was carried out at 150 °C with a 4 wt% catalyst amount at 20:1 methanol/oil molar ratio for 5 h Fe3O4@SBA-15-NH2-HPW prepared by the grafting method exhibited higher reusability, and the yield of biodiesel was more than 80% after 6 times cycles, which made the catalyst have an excellent industrial application prospect.

ZnAlMCM-41: a very ecofriendly and reusable solid acid catalyst for the highly selective synthesis of 1,3-dioxanes by the Prins cyclization of olefins.

The Prins cyclization of styrene (SE) with paraformaldehyde (PFCHO) was conducted with mesoporous ZnAlMCM-41 catalysts for the synthesis of 4-phenyl-1,3-dioxane (4-PDO) using a liquid phase heterogeneous catalytic method. For a comparison study, the Prins cyclization reaction was also conducted over different nanoporous catalysts, e.g. mesoporous solid acid catalysts, AlMCM-41(21) and ZnMCM-41(21), and microporous catalysts, USY, Hβ, HZSM-5, and H-mordenite. The recyclable mesoporous ZnAlMCM-41 catalysts were reused in this reaction to evaluate their catalytic stabilities. Since ZnAlMCM-41(75) has higher catalytic activity than other solid acid catalysts, washed ZnAlMCM-41(75)/W-ZnAlMCM-41(75) was prepared using an efficient chemical treatment method and used with various reaction parameters to find an optimal parameter for the highly selective synthesis of 4-PDO. W-ZnAlMCM-41(75) was also used in the Prins cyclization of olefins with PFCHO and formalin (FN, 37% aqueous solution of formaldehyde (FCHO)) under different reaction conditions to obtain 1,3-dioxanes, which are widely used as solvents or intermediates in organic synthesis. Based on the nature of catalysts used under different reaction conditions, a reasonable plausible reaction mechanism for the Prins cyclization of SE with PFCHO is proposed. Notably, it can be seen from the catalytic results of all catalysts that the W-ZnAlMCM-41(75) catalyst has higher 4-PDO selectivity with exceptional catalytic activity than other microporous and mesoporous catalysts.

Efficiently and Directly Produce Triacetylglycerol from Oils and Fats Over Mesoporous Polymer Solid Acid Catalysts

A series of mesoporous solid acid catalysts (PDS-x) with large BET surface area, superior thermal stability, strong sulfonic acid groups and tunable Bronsted acidity were synthesized by copolymerization of divinylbenzene (DVB) and p-styrenesulfonate hydrate (SPSS). The PDS-x catalysts showed high activity on the direct and efficient production of triacetylglycerol (TAG) by acyl exchange reaction of oils (fats) and acetic acid. The highest TAG yield of 92.2 mol% was obtained on the PDS-x catalysts at a mild condition of 200 o C. By combining SEM, TEM, FT-IR/DRIFT, BET, XRD, and TG-DTG, the key factors that affected the TAG yield were clarified on the PDS-x catalysts. Moreover, the origin of the slow deactivation on these catalysts was elucidated. The large BET surface area and abundant mesopores allowed the contact of large-sized glycerol tristearate with the strong sulfonic acid groups, accounting for the high TAG yield.

Dehydration of sugars to 5-hydroxymethylfurfural and non-stoichiometric formic and levulinic acids over mesoporous Ta and Ta-W oxide solid acid catalysts

A series of mesoporous Ta and Ta-W oxides have been prepared and employed as solid acid catalysts for the dehydration of fructose and glucose to 5-hydroxymethylfurfural (HMF). Solid state 31P MAS NMR spectroscopic results using trimethylphosphine (TMP) as a probe molecule show that the acid strength and the ratio of Brönsted to Lewis acid sites increase gradually with the addition of tungsten in tantalum oxide. It is found that high sugar conversion and HMF selectivity are achieved over catalyst with relatively high ratios of Brönsted to Lewis acid sites. Unexpected stoichiometric excess of formic acid relative to levulinic acid can be observed mainly because of direct decomposition of fructose over Lewis acid sites. The addition of 2-butanol leads to the increase of sugars conversion and the HMF selectivity, especially for the catalyst with high ratio of Brönsted to Lewis acid sites. Among them, Ta7W3 oxide catalyst shows 54% HMF selectivity and good reusability with the addition of 2-butanol by extracting HMF from aqueous phase and removing humins deposed on the surface of the catalyst.

Synthesis and characterization of copper (II)-poly(acrylic acid)/M-MCM-41 nanocomposite as a novel mesoporous solid acid catalyst for the one-pot synthesis of polyhydroquinoline derivatives

In this study, a novel mesoporous silica nanocomposite (MSNC) based on poly(acrylic acid) and amine-functionalized MCM-41 mesoporous silica as amplification agents was constructed via an ultrasonic-assisted method as a straightforward, fast, eco-friendly and it is denoted as M-MCM-41. Then Cu (II) was immobilized on PAA/M-MCM-41 surface and the novel heterogeneous reusable catalyst was fully characterized using appropriate techniques such as Fourier transform infrared (FT-IR), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), field emission scanning electron microscopy (FE-SEM), thermogravimetry analysis (TGA) and N2 adsorption–desorption. The resulting catalyst was successfully used for the condensation of various aromatic aldehydes, dimedone, ß-ketoester and ammonium acetate under solvent-free and mild conditions to yield polyhydroquinoline derivatives in good to excellent yields. Also, the experimental evidence was demonstrated that Cu (II)-PAA/M-MCM-41 nanocomposite could act as a recoverable and reusable nanocatalyst without a meaningful drop in the yield and the reaction time at least four times.

SBA-15/PrN(CH2PO3H2)2 as a novel and efficient mesoporous solid acid catalyst with phosphorous acid tags and its application on the synthesis of new pyrimido[4,5-b]quinolones and pyrido[2,3-d]pyrimidines via anomeric based oxidation

Abstract In this work, SBA-15/PrN(CH2PO3H)2 as a novel and heterogeneous catalyst containing of phosphorous acid groups was fully characterized by using various analysis techniques. A good range of novel pyrido[2,3-d]pyrimidines and pyrimido[4,5-b]quinolines were synthesized in the presence of SBA-15/PrN(CH2PO3H)2 under solvent-free condition. The major advantages of the described method are high yields, short reaction times and reusability of the catalyst. The obtained results from this research will be supported by the idea of rational designs, syntheses and applications of task-specific catalysts and molecules for the development of biomimetic anomeric based oxidation and/or aromatization mechanism.

Synthesis and characterization of butylamine-functionalized Cr(III)–MOF–SO3H: Synergistic effect of the hydrophobic moiety on Cr(III)–MOF–SO3H in esterification reactions

Mesoporous solid acid catalysts with partially hydrophobic moieties, [Cr3O(BDC–SO3H)3−x(BDC–SO3NH3Bu)x]n, were prepared from [Cr3O(BDC–SO3H)3]n (MIL-101(Cr)–SO3H) and BuNH2 for the first time and then characterized by the Brunauer–Emmet–Teller (BET) technique, powder X-ray diffraction, field emission electron microscopy, Fourier transform infrared spectroscopy, and thermal and elemental analyses. The nitrogen adsorption–desorption study showed that the specific surface area and total pore volume of MIL-101(Cr)–SO3H decreased after the reaction with butylamine and formation of [Cr3O(BDC–SO3H)3−x(BDC–SO3NH3Bu)x]n. The prepared materials were used as catalysts to investigate the impact of hydrophobic moieties in esterification yields of phthalic anhydride with several alcohols as a probe reaction. The presence of butylamine as a hydrophobic group on MIL-101(Cr)–SO3H increases the esterification yield significantly for hydrophilic alcohols under solvent-free conditions. Moreover, results showed that [Cr3O(BDC–SO3H)3−x(BDC–SO3NH3Bu)x]n can be recovered and reused for several consecutive reactions without significant loss in catalyst activity.

Preparation and application of ordered mesoporous carbon-based solid acid catalysts for transesterification and epoxidation

Ordered mesoporous carbon (OMC) was prepared via the inverse replication method using SBA-15 as a hard template and sucrose as a carbon precursor. OMC was sulfonated to obtain the solid acid catalysts, such as OMC-SS and OMC-DS, by heating with sulfuric acid or coupling with sulfanilic acid diazonium. TEM and small-angle X-ray diffraction (XRD) results showed that OMC, OMC-SS, and OMC-DS exhibited ordered porous structures. XPS and Raman analysis showed that OMC had graphite structure. N2-BET analysis indicated that OMC, OMC-SS, and OMC-DS had average pore diameters of 3.0–3.3 nm and exhibited bimodal mesopore size distributions. Moreover, N2-BET analysis revealed that OMC, OMC-SS, and OMC-DS had surface areas of 1411, 924 and 1001 m2/g, respectively. The surface acid contents of OMC-SS and OMC-DS were 3.9–4.0 mmol H+/ g and higher than those of OCM (2.8 mmol H+/g). FTIR results demonstrated that –SO3H was present on OMC-SS and OMC-DS. OMC-SS and OMC-DS were used to catalyze the transesterification and epoxidation of waste frying oil. The transesterification reactions catalyzed using OMC-SS and OMC-DS provided the maximum yields of fatty acid methyl esters of 90.3 ± 3.3% and 89.0 ± 2.1%, respectively. The double-bond conversion rates of epoxidation reactions catalyzed using OMC-SS and OMC-DS reached 77.2 ± 1.9% and 68.5 ± 2.6%, respectively. The epoxy yields of epoxidation reactions catalyzed using OMC-SS and OMC-DS were 70.3 ± 2.4% and 65.1 ± 1.8%, respectively.

Preparation of sulfonated ordered mesoporous carbon catalyst and its catalytic performance for esterification of free fatty acids in waste cooking oils.

Sulfonated ordered mesoporous carbon (SO3H-OMC) solid acid catalysts from sucrose were prepared using hard-template method, and their catalytic performance as well as the deactivation mechanism for esterification of free fatty acids (FFAs) in waste cooking oils (WCOs) were evaluated. Effects of sulfonation time, sulfonation temperature and hard template structure type for the textural properties and acid properties of SO3H-OMC were systematically investigated by N2 adsorption–desorption, FT-IR, NH3-TPD, TEM and strong acid density analysis. The results indicated that, SO3H-OMC(s)-6-160 catalyst, which was prepared by using SBA-15 as hard template at sulfonation time of 6 h and sulfonation temperature of 160 °C, had well-ordered mesoporous structure and high –SO3H groups density (2.32 mmol g−1). Compared with SO3H-APC-6-160 catalyst, cation-exchange resin D072 and SO3H-OMC(k)-6-160 catalyst, it was found that the SO3H-OMC(s)-6-160 catalyst exhibited highest activity (FFAs conversion was 93.8%) and good stability for the FFAs esterification, attributed to its 2D-hexagonal channels and hydrophobic surface. The –SO3H groups being leached out of SO3H-OMC catalysts into the liquid phase (especially methanol) would be the main reason causing catalyst deactivation.

A Highly Efficient and Recyclable Solid Acid Catalyst for Synthesis of Spiro-oxindole Dihydroquinazolinones Under Ultrasound Irradiation

A simple, efficient and green procedure for the synthesis of spiro-oxindole dihyfroquinazolinones was developed by multi-component condensation of isatoic anhydride, aniline and isatin in the presence of a novel solid acid catalyst under ultrasound irradiation. The present environmentally benign protocol offers several advantages, such as shorter reaction time, a wide range of functional group tolerance, the use of an inexpensive heterogeneous catalyst, and a high yield of products via a simple experimental and work-up procedure. The mesoporous solid acid catalyst was directly prepared from phytic acid by microwave-sulfonation method without template. The phytic acid based solid acid was fully characterized by means of Fourier transform infrared spectroscopy(FTIR), Raman spectroscopy, X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), and transmission electron microscopy(TEM). The catalyst can be recovered and reused for at least five runs without significant impact on the product yields.