Tungstated zirconia(WO_(3)/ZrO_(2))solid acid catalysts with different WO_(3) contents were prepared by a hydrothermal method and then used in the catalytic aquathermolysis of heavy oil from Xinjiang.The WO_(3)/ZrO_(2...Tungstated zirconia(WO_(3)/ZrO_(2))solid acid catalysts with different WO_(3) contents were prepared by a hydrothermal method and then used in the catalytic aquathermolysis of heavy oil from Xinjiang.The WO_(3)/ZrO_(2) solid acid catalyst was characterized by a range of characterization methods,including X-ray diffraction,NH3-temperature programmed desorption,and pyridine infrared spectroscopy.The WO_(3) content of the WO_(3)/ZrO_(2) catalysts had an important impact on the structure and property of the catalysts.When the WO_(3) mass fraction was 20%,it facilitated the formation of tetragonal zirconia,thereby enhancing the creation of robust acidic sites.Acidity is considered to have a strong impact on the catalytic performance of the aquathermolysis of heavy oil.When the catalyst containing 20%WO_(3) was used to catalyze the aquathermolysis of heavy oil under conditions of 14.5 MPa,340℃,and 24 h,the viscosity of heavy oil decreased from 47266 to 5398 mPa·s and the viscosity reduction rate reached 88.6%.The physicochemical properties of heavy oil before and after the aquathermolysis were analyzed using a saturates,aromatics,resins,and asphaltenes analysis,gas chromatography,elemental analysis,densimeter etc.After the aquathermolysis,the saturate and aromatic contents significantly increased from 43.3%to 48.35%and 19.47%to 21.88%,respectively,with large reductions in the content of resin and asphaltene from 28.22%to 25.06%and 5.36%to 2.03%,respectively.The sulfur and nitrogen contents,and the density of the oil were significantly decreased.These factors were likely the main reasons for promoting the viscosity reduction of heavy oil during the aquathermolysis over the WO_(3)/ZrO_(2) solid acid catalysts.展开更多
A carbon solid acid catalyst was prepared by the sulfonation of partially carbonized peanut shell with concentrated H2SO4. The structure and acidity of the catalyst were characterized by Fourier transform infrared spe...A carbon solid acid catalyst was prepared by the sulfonation of partially carbonized peanut shell with concentrated H2SO4. The structure and acidity of the catalyst were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X‐ray diffraction, thermogravimetric analysis, X‐ray photoelectron spectroscopy, and elemental analysis, which showed that it was an amorphous carbon material composed of aromatic carbon sheets in random orientations. Sulfonic acid groups were present on the surface at a density of 0.81 mmol/g. The carbon solid acid catalyst showed better performance than HZSM‐5 for the esterification of cyclohexene with formic acid. At a3:1 molar ratio of formic acid to cyclohexene, catalyst loading of 0.07 g/mL of cyclohexene, and reaction time of 1 h at 413 K, the cyclohexene conversion was 88.4% with 97.3% selectivity to cyclohexyl formate. The carbon solid acid catalyst showed better reusability than HZSM‐5 because its large pores were minimally affected by the accumulation of oligomerized cyclohexene, which deactivated HZSM‐5. The activity of the carbon solid acid catalyst decreased somewhat in the first two recycles due to the leaching of polycyclic aromatic hydrocarbon containing –SO3H groups and then it remained constant in the following reuse.展开更多
A natural attapulgite (ATP)‐based catalyst, sulfated In2O3‐ATP (SO42-/In2O3‐ATP), was obtained by an impregnation‐calcination method and was used to efficiently and selectively produce the useful platform chem...A natural attapulgite (ATP)‐based catalyst, sulfated In2O3‐ATP (SO42-/In2O3‐ATP), was obtained by an impregnation‐calcination method and was used to efficiently and selectively produce the useful platform chemical 5‐hydroxymethylfurfural (HMF) from hexoses. Some important reaction param‐eters were studied, revealing that Lewis and Br-nsted acid sites on SO42-/In2O3‐ATP catalyze glu‐cose isomerization and fructose dehydration. The yields of HMF from glucose and fructose were 40.2%and 46.2%, respectively, using the optimal conditions of 180℃ for 60 min with 10 wt%of solid acid catalyst in a mixture of γ‐valerolactone‐water (9:1).展开更多
The textural features and acidic properties of sulfated mesoporous lanthana‐zirconia solid acids (SO42?/meso‐La0.1Zr0.9Oδ) were efficiently tuned by modifying the conditions used to prepare the meso‐La0.1Zr0.9O...The textural features and acidic properties of sulfated mesoporous lanthana‐zirconia solid acids (SO42?/meso‐La0.1Zr0.9Oδ) were efficiently tuned by modifying the conditions used to prepare the meso‐La0.1Zr0.9Oδcomposites, such as the molar ratio of the template to La and Zr metal ions (Nt/m), molar ratio of ammonia to La and Zr metal ions (Na/m), hydrothermal temperature (Thydro), and hy‐drothermal time (thydro). The effect of the textural features and acidic properties on the catalytic performance of solid acid catalysts for alkenylation of p‐xylene with phenylacetylene was investi‐gated. Various characterization techniques such as N2 physisorption, X‐ray diffraction, NH3 temper‐ature‐programmed desorption, and thermogravimetric analysis were employed to reveal the rela‐tionship between the nature of catalyst and its catalytic performance. It was found that the catalytic performance significantly depended on the textural features and acidic properties, which were strongly affected by preparation conditions of the meso‐La0.1Zr0.9Oδcomposite. Appropriate acidic sites and high accessibility were required to obtain satisfactory catalytic reactions for this reaction. It was also found that the average crystallite size of t‐ZrO2 affected by the preparation conditions had significant influence on the ultrastrong acidic sites of the catalysts. The optimized SO42?/meso‐La0.1Zr0.9Oδcatalyst exhibited much superior catalytic activity and coke‐resistant stabil‐ity. Moreover, the developed SO42?/meso‐La0.1Zr0.9Oδcatalyst demonstrated excellent catalytic per‐formance for alkenylation of diverse aromatics with phenylacetylene to their correspondingα‐arylstyrenes. Combining the previously established complete regeneration of used catalysts by a facile calcination process with the improved catalytic properties, the developed SO42?/meso‐La0.1Zr0.9Oδ solid acid could be a potential catalyst for industrial production ofα‐arylstyrenes through clean and atom efficient solid‐acid‐mediated Friedel‐Crafts alkenylation of diverse aromatics with phenylacetylene.展开更多
Esterification of acrylic acid(AA) to produce AA esters has widespread application in the chemical industry. A series of water tolerant solid acid catalysts was prepared, and characterized by XRD, nitrogen adsorptio...Esterification of acrylic acid(AA) to produce AA esters has widespread application in the chemical industry. A series of water tolerant solid acid catalysts was prepared, and characterized by XRD, nitrogen adsorption, TGA-DTA, XPS, and ammonia adsorption FTIR. The effects of Si/Al ratio, zirconium sulfate(ZS) loading on HZSM-5 and calcination temperature on the esterification were investigated. When 20% (mass fraction) ZS is loaded on HZSM-5, the conversion of AA reaches 100%. XRD analysis indicates that ZS is highly dispersed on HZSM-5 because no crystalline structure assigned to ZS is found. Catalytic activity and hydrophobicity of ZS supported on HZSM-5 are higher compared with those of parent ZS or HZSM-5. Results show that this kind of novel catalysts is an efficient water tolerant solid acid catalyst for esterification reactions.展开更多
The solid acid SO_4^(2-)/TiO_2 was prepared by immersion method and applied for synthesis of propylene glycol methyl ether acetate(PMA) through esterification reaction of propylene glycol monomethyl ether(PM)and aceti...The solid acid SO_4^(2-)/TiO_2 was prepared by immersion method and applied for synthesis of propylene glycol methyl ether acetate(PMA) through esterification reaction of propylene glycol monomethyl ether(PM)and acetic acid(HAc). The optimal catalyst preparation condition was determined by orthogonal analysis of parameters in a five-factor and four-level test. The obtained solid acid catalysts were characterized in detail by means of X-ray powder diffraction, thermogravimetry, pyridine adsorbed IR analysis, scanning electron microscopy, and BET surface area method. Synthesis of PMA was studied in this paper through experimental investigation of reaction conditions such as temperature, molar ratio of reactants, catalyst dosage and agitation speed. Based on its possible reaction mechanism, a pseudo-homogeneous kinetic model was established and its activation energies E_a^+ and E_a^-,65.68 × 10~3J·mol^(-1) and 57.78 × 10~3J·mol^(-1), were estimated. To prepare shaped solid acid catalyst SO_4^(2-)/TiO_2, the shaping method of impregnation–shaping–impregnation was applied. The optimal molding formulation of solid acid catalyst, obtained from the orthogonal test, was found to be binder 7 wt%, reinforcing agent 20 wt%, pore forming material 2.5 wt%, and lubricant 4 wt%.The results of performance test of catalyst demonstrated that the shaped solid acid catalyst exhibited high activity and stability.展开更多
A new solid acid catalyst,SO4^2-/TiO2 modified with tin,was prepared using a sol-gel method and its physicochemical properties were revealed by nitrogen adsorption-desorption,X-ray powder diffraction,scanning electron...A new solid acid catalyst,SO4^2-/TiO2 modified with tin,was prepared using a sol-gel method and its physicochemical properties were revealed by nitrogen adsorption-desorption,X-ray powder diffraction,scanning electron microscopy,Fourier transform infrared spectroscopy,infrared spectroscopy of adsorbed pyridine,temperature-programmed desorption of ammonia and thermal gravimetric analysis.The structure,acidity and thermal stability of the SO4^2-/TiO2-SnO2 catalyst were studied.Incorporating tin enlarged the specific surface area and decreased crystallite size of the SO4^2-/TiO2 catalyst.The total acid sites of the modified catalyst increased and Bronsted acid strength remarkably increased with increasing tin content.The decomposition temperature of sulfate radical in the modified catalyst was 100 ℃ greater and its mass loss was more than twice that of the SO4^2-/TiO2 catalyst.The SO4^2-/TiO2-SnO2 catalyst was designed to synthesize 1,6-hexanediol diacrylate by esterification of 1,6-hexanediol with crylic acid.The yield of 1,6-hexanediol diacrylate exceeded 87% under the optimal reaction conditions:crylic acid to 1,6-hexanediol molar ratio = 3.5,catalyst loading = 7%,reaction temperature = 130 ℃ and reaction time = 3 h.The modified catalyst exhibited excellent reusability and after 10 cycles the conversion of 1,6-hexanediol was above 81%.展开更多
The kinetics of simultaneous transesterification and esterification with a carbon-based solid acid catalyst was studied.Two solid acid catalysts were prepared by the sulfonation of carbonized vegetable oil asphalt and...The kinetics of simultaneous transesterification and esterification with a carbon-based solid acid catalyst was studied.Two solid acid catalysts were prepared by the sulfonation of carbonized vegetable oil asphalt and petroleum asphalt.These catalysts were characterized on the basis of elemental analysis,acidity site concentration,the Brunauer-Emmett-Teller(BET)surface area and pore size.The kinetic parameters with the two catalysts were determined,and the reaction system can be described as a pseudo homogeneous catalyzed reaction.All the forward and reverse reactions follow second order kinetics.The calculated concentration values from the kinetic equations are in good agreement with experimental values.展开更多
A new solid acid was prepared by trifluoromethanesulfonic acid (TFMSA) impregnation into an acid‐treated attapulgite (ATA). Di(1‐naphthyl)methane (DNM) hydrocracking was used as the probe reaction to evaluat...A new solid acid was prepared by trifluoromethanesulfonic acid (TFMSA) impregnation into an acid‐treated attapulgite (ATA). Di(1‐naphthyl)methane (DNM) hydrocracking was used as the probe reaction to evaluate the catalytic performance of TFMSA/ATA for cleaving Car–Calk bridged bonds in coals. The results show that DNM was specifically hydrocracked to naphthalene and 1‐methylnaphthalene over TFMSA/ATA in methanol in the absence of gaseous hydrogen. In partic‐ular, TFMSA/ATA was demonstrated to be stable after four cycles with slight loss in catalytic activi‐ty. Furthermore, a proposed H+transfer mechanism successfully interprets the TFMSA/ATA‐cata‐lyzed hydrocracking reaction of DNM.展开更多
Nitro aromatic compound can be obtained in high yields via nitration of aromatic compound with wet carbon-based solid acid and NaNO_3 under solvent free oxidation at room temperature.
Three Keggin-type heteropolyanions, namely H3PMo12O40-13H2O, (NH4)3PMo12O40·4H2O and H3PW12O40·13H2O were prepared and tested in the ring-opening polymerization reaction of tetrahydrofuran. The effects of ...Three Keggin-type heteropolyanions, namely H3PMo12O40-13H2O, (NH4)3PMo12O40·4H2O and H3PW12O40·13H2O were prepared and tested in the ring-opening polymerization reaction of tetrahydrofuran. The effects of the counter-cation (H+, NH4+) and the peripheral atoms (Mo, W) on the polymerization were investigated. It has been found that when the protons of H3PMo12O40·13H2O were replaced by the ammonium cations the polymerization rate decreased dramatically. Whereas, when the peripheral atoms (Mo) were replaced by their homologous (W), the polymerization rate increased twofold. As for the viscosity average molecular weight (My) of polymer products, it was found that the high molecular weight (7930) was obtained by using H3PW12O40·13H2O. The molecular weight (My) obtained by H3PMo12O40·13H2O and (NH4)H3PMo12O40·13H2O was 6470 and 6810, respectively.展开更多
Biomass-derived hexose sugars, the most abundant renewable resources in the world, have potential to be the sustainable resources for production of platform chemicals. Here, con- version of glucose is investigated by ...Biomass-derived hexose sugars, the most abundant renewable resources in the world, have potential to be the sustainable resources for production of platform chemicals. Here, con- version of glucose is investigated by using sulfonated graphene (rGO-SOaH) as solid acid catalyst in water without any organic solvent. At first, graphene functionalized with sulfonic acid groups is prepared by using Nail and propane sultone, and then it is characterized by means of XPS, FT-IR, and TEM to confirm the existence of the sulfonic acid groups. The catalytic activity of rGO-SOaH in the conversion of glucose to valuable chemicals is studied under different reaction conditions. The maximum yield of 5-hydroxymethylfurfural (HMF) is 28.8%, and the total yield of formic acid, lactic acid and HMF is 51.94% when the reaction is conducted at the optimized reaction condition. In addition, the rGO-SOaH gives a rela- tively high total yield of the three kinds of products after five run experiments, indicating that the catalyst shows good thermal stability.展开更多
Anovel solid acid catalyst, which was prepared from sodium alginate (SA) and metal chlorides and characterized with XRD and FT-IR spectrometry, was used for the preparation of biodiesel via esterification reaction. Th...Anovel solid acid catalyst, which was prepared from sodium alginate (SA) and metal chlorides and characterized with XRD and FT-IR spectrometry, was used for the preparation of biodiesel via esterification reaction. The study results showed that the aluminum-alginate complex prepared in a cheap and easy way exhibited high catalytic activity, and a 92.6% conversion of methyl oleate was obtained in the presence of 4m% of catalyst dosage upon refluxing for 3h of methanol and acid mixed in a molar ratio of 10:1. It should be noted that the catalyst can be applied to the esterification reaction of fatty acids with various carbon chain length on methanol or different short chain alcohols, indicating that the catalyst is suitable for the preparation of biodiesel from waste oils with a high acid value.展开更多
Two kinds of mesoporous carbon solid acids(LDMCE-SO3H and LDMCS-SO3H)were successfully prepared using masson pine alkali lignin as carbon source by evaporation-induced self-assembly(EISA)and salt-induced selfassembly(...Two kinds of mesoporous carbon solid acids(LDMCE-SO3H and LDMCS-SO3H)were successfully prepared using masson pine alkali lignin as carbon source by evaporation-induced self-assembly(EISA)and salt-induced selfassembly(SISA)followed by sulfonation,respectively.In terms of preparation process,SISA(self-assembly in water and preparation time of 2 days)is greener and simpler than EISA(self-assembly in ethanol and preparation time of 7 days).The prepared LDMCE-SO3H and LDMCS-SO3H exhibit obvious differences in structural characteristics such as pore channel structure,specific surface area,mesopore volume and the density of-SO3H groups.Furthermore,the catalytic performances of LDMCE-SO3H and LDMCS-SO3H were investigated in the hydrolysis of microcrystalline cellulose in water,and the glucose yields of 48.99%and 54.42%were obtained under the corresponding optimal reaction conditions.More importantly,the glucose yields still reached 28.85%and 30.35%after five runs,and restored to 39.02%and 45.98%through catalysts regeneration,respectively,demonstrating that LDMCE-SO3H and LDMCS-SO3H have excellent recyclability and regenerability.展开更多
A silica-supported zirconium based solid acid (ZS) has been used as catalyst for the Fries rearrangement of phenyl acetate (PA). The catalyst showed a higher PA conversion activity and a much higher selectivity for o...A silica-supported zirconium based solid acid (ZS) has been used as catalyst for the Fries rearrangement of phenyl acetate (PA). The catalyst showed a higher PA conversion activity and a much higher selectivity for o-hydroxyacetophenone (o-HAP) than for strongly acidic zeolite catalysts. The supported catalyst was characterized by XRD, IR, XPS, pyridine-TPD and the surface area measurements. The catalytic properties were influenced significantly by pretreatment temperature.展开更多
Wet carbon-based solid acid and potassium permanganate were used as new reagents for oxidation of alcohols to their corresponding aldehydes and ketones in heterogeneous mixtures. The experiments were done moderately a...Wet carbon-based solid acid and potassium permanganate were used as new reagents for oxidation of alcohols to their corresponding aldehydes and ketones in heterogeneous mixtures. The experiments were done moderately at mild condition and high yields in suitable times were obtained.展开更多
Mesoporous molecular sieve with Al-promoted sulfated rirconia (SZA) based strong solid acid nano-particles within its mesoporous channels was synthesized by using a one-step incipient wetness impregnation method with ...Mesoporous molecular sieve with Al-promoted sulfated rirconia (SZA) based strong solid acid nano-particles within its mesoporous channels was synthesized by using a one-step incipient wetness impregnation method with zirconium sulfate and aluminum sulfate as the precursors. The assemblies of SZA/MCM-41 were obtained by thermal decomposition of the precursors in air.The resultant composite was characterized with various techniques such as nitrogen physisorption, X-ray diffraction, SEM and TEM. It was shown that the well-ordered channels of MCM-41 arranged in hexagonal arrays as well as the hollow tubular morphology was retained. The strong solid acid nanoparticles were isolated born each other and highly, dispersed in the channels. Nitrogen sorption showed the expected decrease in pore volume. The catalytic activity of SZA/MCM-41 composite in the isomerization of n-butane was dramatically improved in comparison to bulk SZA or SZA/silica.展开更多
Biomass is a green and producible source of energy and chemicals.Hence,developing high-efficiency catalysts for biomass utilization and transformation is urgently demanded.Metal-organic framework(MOF)-based solid acid...Biomass is a green and producible source of energy and chemicals.Hence,developing high-efficiency catalysts for biomass utilization and transformation is urgently demanded.Metal-organic framework(MOF)-based solid acid materials have been considered as promising catalysts in biomass transformation.In this review,we first introduce the genre of Lewis acid and Brønsted acid sites commonly generated in MOFs or MOF-based composites.Then,the methods for the generation and adjustment of corresponding acid sites are overviewed.Next,the catalytic applications of MOF-based solid acid materials in various biomass transformation reactions are summarized and discussed.Furthermore,based on our personal insights,the challenges and outlook on the future development of MOF-based solid acid catalysts are provided.We hope that this review will provide an instructive roadmap for future research on MOFs and MOF-based composites for biomass transformation.展开更多
The novel solid acid with both sulfonic and carbonyl acid groups has been synthesized from 3-((2-sulfoethoxy) carbonyl)acrylic acid and tetraethyl orthosilicate(TEOS). The catalytic activities were investigated throug...The novel solid acid with both sulfonic and carbonyl acid groups has been synthesized from 3-((2-sulfoethoxy) carbonyl)acrylic acid and tetraethyl orthosilicate(TEOS). The catalytic activities were investigated through the acetalization. The results showed that the novel solid acid was very efficient for the reactions with the high yields. The high acidity, high stability and reusability were the key feature of the novel solid acid. Moreover, the sulfonic and carbonyl acid groups could cooperate during the catalytic process, which improved its catalytic activities. The catalyst shows recyclability, and hold great potential for replacement of homogeneous catalysts.展开更多
The catalytic hydrolysis of dichlorodifluoromethane (CFC-12) was investigated over solid acid Ti(SO_4)_2. The catalytic activity decreased with the calcination temperature. When space velocity was 6 1 h^(-1) g-cat^(-1...The catalytic hydrolysis of dichlorodifluoromethane (CFC-12) was investigated over solid acid Ti(SO_4)_2. The catalytic activity decreased with the calcination temperature. When space velocity was 6 1 h^(-1) g-cat^(-1). the CPC-12 conversion at 310C over Ti(SO_4)_2 calcined at 350C remained about 98.5% during 360 h on stream. and the selectivity to by-products remained zero. The findings enlarged the scope of traditional catalyst systems for the CFCs decomposition.展开更多
基金the financial support from the Open Fund Project of the National Oil Shale Exploitation Research and Development Center,China(No.33550000-22-ZC0613-0255)the Graduate Student Innovation and Practical Ability Training Program of Xi’an Shiyou University(No.YCS23213098)+3 种基金the National Natural Science Foundation of China(No.52274039)the Natural Science Basic Research Plan in Shaanxi Province of China(Program No.2024JC-YBMS-085)the CNPC Innovation Found(No.2022DQ02-0402)The authors also thank the Modern Analysis and Test Center of Xi’an Shiyou University for their help with the characterization of catalysts and analysis of products.
文摘Tungstated zirconia(WO_(3)/ZrO_(2))solid acid catalysts with different WO_(3) contents were prepared by a hydrothermal method and then used in the catalytic aquathermolysis of heavy oil from Xinjiang.The WO_(3)/ZrO_(2) solid acid catalyst was characterized by a range of characterization methods,including X-ray diffraction,NH3-temperature programmed desorption,and pyridine infrared spectroscopy.The WO_(3) content of the WO_(3)/ZrO_(2) catalysts had an important impact on the structure and property of the catalysts.When the WO_(3) mass fraction was 20%,it facilitated the formation of tetragonal zirconia,thereby enhancing the creation of robust acidic sites.Acidity is considered to have a strong impact on the catalytic performance of the aquathermolysis of heavy oil.When the catalyst containing 20%WO_(3) was used to catalyze the aquathermolysis of heavy oil under conditions of 14.5 MPa,340℃,and 24 h,the viscosity of heavy oil decreased from 47266 to 5398 mPa·s and the viscosity reduction rate reached 88.6%.The physicochemical properties of heavy oil before and after the aquathermolysis were analyzed using a saturates,aromatics,resins,and asphaltenes analysis,gas chromatography,elemental analysis,densimeter etc.After the aquathermolysis,the saturate and aromatic contents significantly increased from 43.3%to 48.35%and 19.47%to 21.88%,respectively,with large reductions in the content of resin and asphaltene from 28.22%to 25.06%and 5.36%to 2.03%,respectively.The sulfur and nitrogen contents,and the density of the oil were significantly decreased.These factors were likely the main reasons for promoting the viscosity reduction of heavy oil during the aquathermolysis over the WO_(3)/ZrO_(2) solid acid catalysts.
基金supported by the National Natural Science Foundation of China(2123600121176056)+1 种基金the Programme for 100 Excellent Talents in Universities of Hebei Province(II)(BR2-208)the Natural Science Foundation of Hebei Province(B2015202228)~~
文摘A carbon solid acid catalyst was prepared by the sulfonation of partially carbonized peanut shell with concentrated H2SO4. The structure and acidity of the catalyst were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X‐ray diffraction, thermogravimetric analysis, X‐ray photoelectron spectroscopy, and elemental analysis, which showed that it was an amorphous carbon material composed of aromatic carbon sheets in random orientations. Sulfonic acid groups were present on the surface at a density of 0.81 mmol/g. The carbon solid acid catalyst showed better performance than HZSM‐5 for the esterification of cyclohexene with formic acid. At a3:1 molar ratio of formic acid to cyclohexene, catalyst loading of 0.07 g/mL of cyclohexene, and reaction time of 1 h at 413 K, the cyclohexene conversion was 88.4% with 97.3% selectivity to cyclohexyl formate. The carbon solid acid catalyst showed better reusability than HZSM‐5 because its large pores were minimally affected by the accumulation of oligomerized cyclohexene, which deactivated HZSM‐5. The activity of the carbon solid acid catalyst decreased somewhat in the first two recycles due to the leaching of polycyclic aromatic hydrocarbon containing –SO3H groups and then it remained constant in the following reuse.
基金supported by the Fundamental Research Funds for the Central Universities (TD2011-11,BLYJ201519)Beijing Higher Education Young Elite Teacher Project (YETP0765)+2 种基金National Natural Science Foundation of China (31170556)New Century Excellent Talents in University (NCET-13-0671)State Forestry Administration of China (201204803)~~
文摘A natural attapulgite (ATP)‐based catalyst, sulfated In2O3‐ATP (SO42-/In2O3‐ATP), was obtained by an impregnation‐calcination method and was used to efficiently and selectively produce the useful platform chemical 5‐hydroxymethylfurfural (HMF) from hexoses. Some important reaction param‐eters were studied, revealing that Lewis and Br-nsted acid sites on SO42-/In2O3‐ATP catalyze glu‐cose isomerization and fructose dehydration. The yields of HMF from glucose and fructose were 40.2%and 46.2%, respectively, using the optimal conditions of 180℃ for 60 min with 10 wt%of solid acid catalyst in a mixture of γ‐valerolactone‐water (9:1).
基金financially supported by the National Natural Science Foundation of China (21276041)the Program for New Century Excellent Talents in University of Ministry of Education (NCET-12-0079)+1 种基金the Natural Science Foundation of Liaoning Province (2015020200)the Fundamental Research Funds for the Central Universities (DUT15LK41)~~
文摘The textural features and acidic properties of sulfated mesoporous lanthana‐zirconia solid acids (SO42?/meso‐La0.1Zr0.9Oδ) were efficiently tuned by modifying the conditions used to prepare the meso‐La0.1Zr0.9Oδcomposites, such as the molar ratio of the template to La and Zr metal ions (Nt/m), molar ratio of ammonia to La and Zr metal ions (Na/m), hydrothermal temperature (Thydro), and hy‐drothermal time (thydro). The effect of the textural features and acidic properties on the catalytic performance of solid acid catalysts for alkenylation of p‐xylene with phenylacetylene was investi‐gated. Various characterization techniques such as N2 physisorption, X‐ray diffraction, NH3 temper‐ature‐programmed desorption, and thermogravimetric analysis were employed to reveal the rela‐tionship between the nature of catalyst and its catalytic performance. It was found that the catalytic performance significantly depended on the textural features and acidic properties, which were strongly affected by preparation conditions of the meso‐La0.1Zr0.9Oδcomposite. Appropriate acidic sites and high accessibility were required to obtain satisfactory catalytic reactions for this reaction. It was also found that the average crystallite size of t‐ZrO2 affected by the preparation conditions had significant influence on the ultrastrong acidic sites of the catalysts. The optimized SO42?/meso‐La0.1Zr0.9Oδcatalyst exhibited much superior catalytic activity and coke‐resistant stabil‐ity. Moreover, the developed SO42?/meso‐La0.1Zr0.9Oδcatalyst demonstrated excellent catalytic per‐formance for alkenylation of diverse aromatics with phenylacetylene to their correspondingα‐arylstyrenes. Combining the previously established complete regeneration of used catalysts by a facile calcination process with the improved catalytic properties, the developed SO42?/meso‐La0.1Zr0.9Oδ solid acid could be a potential catalyst for industrial production ofα‐arylstyrenes through clean and atom efficient solid‐acid‐mediated Friedel‐Crafts alkenylation of diverse aromatics with phenylacetylene.
基金Supported by the Research Fund for the Doctoral Program of Higher Education(No20050010014)the China Petroleum &Chemical Corporation ( No X503015 )the Key Discipline Construction Foundation of Beijing Education Committee ( NoXK100100643)
文摘Esterification of acrylic acid(AA) to produce AA esters has widespread application in the chemical industry. A series of water tolerant solid acid catalysts was prepared, and characterized by XRD, nitrogen adsorption, TGA-DTA, XPS, and ammonia adsorption FTIR. The effects of Si/Al ratio, zirconium sulfate(ZS) loading on HZSM-5 and calcination temperature on the esterification were investigated. When 20% (mass fraction) ZS is loaded on HZSM-5, the conversion of AA reaches 100%. XRD analysis indicates that ZS is highly dispersed on HZSM-5 because no crystalline structure assigned to ZS is found. Catalytic activity and hydrophobicity of ZS supported on HZSM-5 are higher compared with those of parent ZS or HZSM-5. Results show that this kind of novel catalysts is an efficient water tolerant solid acid catalyst for esterification reactions.
基金Supported by the National Natural Science Foundation of China(21306025,21576053)the International Science&Technology Cooperation Program of China(2013DFR90540)
文摘The solid acid SO_4^(2-)/TiO_2 was prepared by immersion method and applied for synthesis of propylene glycol methyl ether acetate(PMA) through esterification reaction of propylene glycol monomethyl ether(PM)and acetic acid(HAc). The optimal catalyst preparation condition was determined by orthogonal analysis of parameters in a five-factor and four-level test. The obtained solid acid catalysts were characterized in detail by means of X-ray powder diffraction, thermogravimetry, pyridine adsorbed IR analysis, scanning electron microscopy, and BET surface area method. Synthesis of PMA was studied in this paper through experimental investigation of reaction conditions such as temperature, molar ratio of reactants, catalyst dosage and agitation speed. Based on its possible reaction mechanism, a pseudo-homogeneous kinetic model was established and its activation energies E_a^+ and E_a^-,65.68 × 10~3J·mol^(-1) and 57.78 × 10~3J·mol^(-1), were estimated. To prepare shaped solid acid catalyst SO_4^(2-)/TiO_2, the shaping method of impregnation–shaping–impregnation was applied. The optimal molding formulation of solid acid catalyst, obtained from the orthogonal test, was found to be binder 7 wt%, reinforcing agent 20 wt%, pore forming material 2.5 wt%, and lubricant 4 wt%.The results of performance test of catalyst demonstrated that the shaped solid acid catalyst exhibited high activity and stability.
文摘A new solid acid catalyst,SO4^2-/TiO2 modified with tin,was prepared using a sol-gel method and its physicochemical properties were revealed by nitrogen adsorption-desorption,X-ray powder diffraction,scanning electron microscopy,Fourier transform infrared spectroscopy,infrared spectroscopy of adsorbed pyridine,temperature-programmed desorption of ammonia and thermal gravimetric analysis.The structure,acidity and thermal stability of the SO4^2-/TiO2-SnO2 catalyst were studied.Incorporating tin enlarged the specific surface area and decreased crystallite size of the SO4^2-/TiO2 catalyst.The total acid sites of the modified catalyst increased and Bronsted acid strength remarkably increased with increasing tin content.The decomposition temperature of sulfate radical in the modified catalyst was 100 ℃ greater and its mass loss was more than twice that of the SO4^2-/TiO2 catalyst.The SO4^2-/TiO2-SnO2 catalyst was designed to synthesize 1,6-hexanediol diacrylate by esterification of 1,6-hexanediol with crylic acid.The yield of 1,6-hexanediol diacrylate exceeded 87% under the optimal reaction conditions:crylic acid to 1,6-hexanediol molar ratio = 3.5,catalyst loading = 7%,reaction temperature = 130 ℃ and reaction time = 3 h.The modified catalyst exhibited excellent reusability and after 10 cycles the conversion of 1,6-hexanediol was above 81%.
文摘The kinetics of simultaneous transesterification and esterification with a carbon-based solid acid catalyst was studied.Two solid acid catalysts were prepared by the sulfonation of carbonized vegetable oil asphalt and petroleum asphalt.These catalysts were characterized on the basis of elemental analysis,acidity site concentration,the Brunauer-Emmett-Teller(BET)surface area and pore size.The kinetic parameters with the two catalysts were determined,and the reaction system can be described as a pseudo homogeneous catalyzed reaction.All the forward and reverse reactions follow second order kinetics.The calculated concentration values from the kinetic equations are in good agreement with experimental values.
基金supported by the Fundamental Research Fund for the Central Universities (China University of Mining & Technology,2014ZDPY34)the Priority Academic Program Development of Jiangsu Higher Education Institutions~~
文摘A new solid acid was prepared by trifluoromethanesulfonic acid (TFMSA) impregnation into an acid‐treated attapulgite (ATA). Di(1‐naphthyl)methane (DNM) hydrocracking was used as the probe reaction to evaluate the catalytic performance of TFMSA/ATA for cleaving Car–Calk bridged bonds in coals. The results show that DNM was specifically hydrocracked to naphthalene and 1‐methylnaphthalene over TFMSA/ATA in methanol in the absence of gaseous hydrogen. In partic‐ular, TFMSA/ATA was demonstrated to be stable after four cycles with slight loss in catalytic activi‐ty. Furthermore, a proposed H+transfer mechanism successfully interprets the TFMSA/ATA‐cata‐lyzed hydrocracking reaction of DNM.
文摘Nitro aromatic compound can be obtained in high yields via nitration of aromatic compound with wet carbon-based solid acid and NaNO_3 under solvent free oxidation at room temperature.
基金supported by the Deanship of Scientific Research,King Saud University(No.M/202) and SABIC Company
文摘Three Keggin-type heteropolyanions, namely H3PMo12O40-13H2O, (NH4)3PMo12O40·4H2O and H3PW12O40·13H2O were prepared and tested in the ring-opening polymerization reaction of tetrahydrofuran. The effects of the counter-cation (H+, NH4+) and the peripheral atoms (Mo, W) on the polymerization were investigated. It has been found that when the protons of H3PMo12O40·13H2O were replaced by the ammonium cations the polymerization rate decreased dramatically. Whereas, when the peripheral atoms (Mo) were replaced by their homologous (W), the polymerization rate increased twofold. As for the viscosity average molecular weight (My) of polymer products, it was found that the high molecular weight (7930) was obtained by using H3PW12O40·13H2O. The molecular weight (My) obtained by H3PMo12O40·13H2O and (NH4)H3PMo12O40·13H2O was 6470 and 6810, respectively.
基金This work sic Research the National is supported by the National Ba- Program of China (No.2011CB921403), Natural Science Foundation of China (No.51073147), and the Natural Science Foundation of Anhui Province (No.1408085MKL03).
文摘Biomass-derived hexose sugars, the most abundant renewable resources in the world, have potential to be the sustainable resources for production of platform chemicals. Here, con- version of glucose is investigated by using sulfonated graphene (rGO-SOaH) as solid acid catalyst in water without any organic solvent. At first, graphene functionalized with sulfonic acid groups is prepared by using Nail and propane sultone, and then it is characterized by means of XPS, FT-IR, and TEM to confirm the existence of the sulfonic acid groups. The catalytic activity of rGO-SOaH in the conversion of glucose to valuable chemicals is studied under different reaction conditions. The maximum yield of 5-hydroxymethylfurfural (HMF) is 28.8%, and the total yield of formic acid, lactic acid and HMF is 51.94% when the reaction is conducted at the optimized reaction condition. In addition, the rGO-SOaH gives a rela- tively high total yield of the three kinds of products after five run experiments, indicating that the catalyst shows good thermal stability.
基金financially supported by the International Science & Technology Cooperation Program of China(No.2010DFB60840)the Key Science and Technology Project of Guizhou Province(No.20076004)+1 种基金the Social Development S&T Program(No.SZ-[2009]3011)the National Key Technology R&D Program(No.2006BAD07A12)
文摘Anovel solid acid catalyst, which was prepared from sodium alginate (SA) and metal chlorides and characterized with XRD and FT-IR spectrometry, was used for the preparation of biodiesel via esterification reaction. The study results showed that the aluminum-alginate complex prepared in a cheap and easy way exhibited high catalytic activity, and a 92.6% conversion of methyl oleate was obtained in the presence of 4m% of catalyst dosage upon refluxing for 3h of methanol and acid mixed in a molar ratio of 10:1. It should be noted that the catalyst can be applied to the esterification reaction of fatty acids with various carbon chain length on methanol or different short chain alcohols, indicating that the catalyst is suitable for the preparation of biodiesel from waste oils with a high acid value.
基金financial support from the National Natural Science Foundation of China(grant No.21706085)Subsidized Project for Postgraduates’Innovative Fund in Scientific Research of Huaqiao Universitythe Foundation of Key Laboratory of Pulp and Paper Science and Technology of Ministry of Education/Shandong Province of China(grant No.KF201804)。
文摘Two kinds of mesoporous carbon solid acids(LDMCE-SO3H and LDMCS-SO3H)were successfully prepared using masson pine alkali lignin as carbon source by evaporation-induced self-assembly(EISA)and salt-induced selfassembly(SISA)followed by sulfonation,respectively.In terms of preparation process,SISA(self-assembly in water and preparation time of 2 days)is greener and simpler than EISA(self-assembly in ethanol and preparation time of 7 days).The prepared LDMCE-SO3H and LDMCS-SO3H exhibit obvious differences in structural characteristics such as pore channel structure,specific surface area,mesopore volume and the density of-SO3H groups.Furthermore,the catalytic performances of LDMCE-SO3H and LDMCS-SO3H were investigated in the hydrolysis of microcrystalline cellulose in water,and the glucose yields of 48.99%and 54.42%were obtained under the corresponding optimal reaction conditions.More importantly,the glucose yields still reached 28.85%and 30.35%after five runs,and restored to 39.02%and 45.98%through catalysts regeneration,respectively,demonstrating that LDMCE-SO3H and LDMCS-SO3H have excellent recyclability and regenerability.
文摘A silica-supported zirconium based solid acid (ZS) has been used as catalyst for the Fries rearrangement of phenyl acetate (PA). The catalyst showed a higher PA conversion activity and a much higher selectivity for o-hydroxyacetophenone (o-HAP) than for strongly acidic zeolite catalysts. The supported catalyst was characterized by XRD, IR, XPS, pyridine-TPD and the surface area measurements. The catalytic properties were influenced significantly by pretreatment temperature.
文摘Wet carbon-based solid acid and potassium permanganate were used as new reagents for oxidation of alcohols to their corresponding aldehydes and ketones in heterogeneous mixtures. The experiments were done moderately at mild condition and high yields in suitable times were obtained.
文摘Mesoporous molecular sieve with Al-promoted sulfated rirconia (SZA) based strong solid acid nano-particles within its mesoporous channels was synthesized by using a one-step incipient wetness impregnation method with zirconium sulfate and aluminum sulfate as the precursors. The assemblies of SZA/MCM-41 were obtained by thermal decomposition of the precursors in air.The resultant composite was characterized with various techniques such as nitrogen physisorption, X-ray diffraction, SEM and TEM. It was shown that the well-ordered channels of MCM-41 arranged in hexagonal arrays as well as the hollow tubular morphology was retained. The strong solid acid nanoparticles were isolated born each other and highly, dispersed in the channels. Nitrogen sorption showed the expected decrease in pore volume. The catalytic activity of SZA/MCM-41 composite in the isomerization of n-butane was dramatically improved in comparison to bulk SZA or SZA/silica.
基金funded by the National Natural Sci-ence Foundation of China(No.21905195)Natural Science Foundation of Tianjin City(No.20JCYBJC00800)PEIYANG Young Scholars Program of Tianjin University(No.2020XRX-0023).
文摘Biomass is a green and producible source of energy and chemicals.Hence,developing high-efficiency catalysts for biomass utilization and transformation is urgently demanded.Metal-organic framework(MOF)-based solid acid materials have been considered as promising catalysts in biomass transformation.In this review,we first introduce the genre of Lewis acid and Brønsted acid sites commonly generated in MOFs or MOF-based composites.Then,the methods for the generation and adjustment of corresponding acid sites are overviewed.Next,the catalytic applications of MOF-based solid acid materials in various biomass transformation reactions are summarized and discussed.Furthermore,based on our personal insights,the challenges and outlook on the future development of MOF-based solid acid catalysts are provided.We hope that this review will provide an instructive roadmap for future research on MOFs and MOF-based composites for biomass transformation.
基金Supported by the Chinese National General Administration of Quality Supervision,Inspection and Quarantine(2012IK048,2011IK041)the National Natural Science Foundation of China(21103111)
文摘The novel solid acid with both sulfonic and carbonyl acid groups has been synthesized from 3-((2-sulfoethoxy) carbonyl)acrylic acid and tetraethyl orthosilicate(TEOS). The catalytic activities were investigated through the acetalization. The results showed that the novel solid acid was very efficient for the reactions with the high yields. The high acidity, high stability and reusability were the key feature of the novel solid acid. Moreover, the sulfonic and carbonyl acid groups could cooperate during the catalytic process, which improved its catalytic activities. The catalyst shows recyclability, and hold great potential for replacement of homogeneous catalysts.
文摘The catalytic hydrolysis of dichlorodifluoromethane (CFC-12) was investigated over solid acid Ti(SO_4)_2. The catalytic activity decreased with the calcination temperature. When space velocity was 6 1 h^(-1) g-cat^(-1). the CPC-12 conversion at 310C over Ti(SO_4)_2 calcined at 350C remained about 98.5% during 360 h on stream. and the selectivity to by-products remained zero. The findings enlarged the scope of traditional catalyst systems for the CFCs decomposition.