616-38-6Relevant articles and documents
Direct synthesis of dimethyl carbonate from methanol and carbon dioxide over Ga2O3/Ce0.6Zr0.4O2 catalysts: Effect of acidity and basicity of the catalysts
Lee, Hye Jin,Park, Sunyoung,Song, In Kyu,Jung, Ji Chul
, p. 531 - 537 (2011)
Ce X Zr1-X O2 catalysts with different cerium content (X) (X = 0, 0.2, 0.4, 0.5, 0.6, 0.8, and 1.0) were prepared by a sol-gel method for use in the direct synthesis of dimethyl carbonate from methanol and carbon dioxide. Among these catalysts, Ce0.6Zr 0.4O2 was found to show the best catalytic performance. In order to enhance the acidity and basicity of Ce0.6Zr 0.4O2 catalyst, Ga2O3 was supported on Ce0.6Zr0.4O2 (XGa2O 3/Ce0.6Zr0.4O2 (X = 1, 5, 10, and 15)) by an incipient wetness impregnation method with a variation of Ga 2O3 content (X, wt%). Effect of acidity and basicity of Ga2O3/Ce0.6Zr0.4O2 on the catalytic performance in the direct synthesis of dimethyl carbonate was investigated using NH3-TPD and CO2-TPD experiments. Experimental results revealed that both acidity and basicity of the catalysts played a key role in determining the catalytic performance in the direct synthesis of dimethyl carbonate from methanol and carbon dioxide. Large acidity and basicity of the catalyst facilitated the formation of dimethyl carbonate. The amount of dimethyl carbonate produced over XGa2O 3/Ce0.6Zr0.4O2 catalysts increased with increasing both acidity and basicity of the catalysts. Among the catalysts tested, 5Ga2O3/Ce0.6Zr0.4O 2, which retained the largest acidity and basicity, showed the best catalytic performance in the direct synthesis of dimethyl carbonate from methanol and carbon dioxide. Graphical Abstract: In the direct synthesis of dimethyl carbonate (DMC) from methanol and carbon dioxide over Ga 2O3/Ce0.6Zr0.4O2 catalysts, the amount of DMC showed a volcano-shaped curve with respect to Ga2O3 content. The amount of DMC increased with increasing both acidity and basicity of the catalysts [Figure not available: see fulltext.]
Efficient fixation and conversion of CO2 into dimethyl carbonate catalyzed by an imidazolium containing tri-cationic ionic liquid/super base system
Chaugule, Avinash A.,Tamboli, Ashif H.,Kim, Hern
, p. 42279 - 42287 (2016)
The synthesis route used to prepare dimethyl carbonate from CO2 and methanol is a most attractive route from a green chemistry point of view. Herein, we systematically studied binary catalyst systems for the synthesis of dimethyl carbonate from CO2 and methanol. It was found that [GLY(mim)3][NTf2]3IL/DBU, [GLY(mim)3][NTf2]3/MTBD and [GLY(mim)3][NTf2]3/TBD are effective binary catalysts for the direct synthesis of DMC without the need of a dehydration system. In particular, the [GLY(mim)3][NTf2]3 IL/1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) system was found to have 37% MeOH conversion and 93% DMC selectivity under mild reaction conditions. However, the tri-imidazolium salts were compatible with DBU for effective CO2 adsorption, possibly because of the reactive C(2)-H in the imidazolium ring. Furthermore, the [GLY(mim)3][NTf2]3 IL/DBU catalytic system could be easily recovered and reused three times without any obvious loss of catalytic activity. The catalytic reactivity of [GLY(mim)3][NTf2]3 IL/DBU for the synthesis of DMC was proved by its predictable mechanism on the basis of 13C NMR spectroscopy.
Triorganotin(iv) cation-promoted dimethyl carbonate synthesis from CO2 and methanol: Solution and solid-state characterization of an unexpected diorganotin(iv)-oxo cluster
?vec, Petr,Cattey, Hélène,R??i?ková, Zdeňka,Holub, Josef,R??i?ka, Ale?,Plasseraud, Laurent
, p. 8253 - 8260 (2018)
Two novel C,N-chelated organotin(iv) complexes bearing weakly coordinating carborane moieties were prepared by the reaction of the corresponding C,N-chelated organotin(iv) chloride (i.e. LCNR2SnCl, R = n-Bu (1) and Ph (2); LCN = 2-(N,N-dimethylaminomethyl)phenyl)) with monocarba-closo-dodecaborate silver salt (AgCB11H12; Ag·3). Both products of the metathesis, [LCN(n-Bu)2Sn]+[CB11H12]- (4) and [LCNPh2Sn]+ [CB11H12]- (5), respectively, were characterized by both multinuclear NMR spectroscopy and elemental analysis. The instability of 4 and 5 towards water is discussed. The solid-state structure of LCN(n-Bu)2SnOH·B(C6F5)3 (4a) as a model compound with a Sn-O(H)?B linkage is also reported. The evaluation of the catalytic activity of 4 and 5 was carried out within the direct synthesis of dimethyl carbonate (DMC) from methanol and CO2. While 5 was shown to be definitively inactive, presumably due to cleavage of the Sn-Ph bond, compound 4 exhibits a beneficial action, since it leads to an amount of DMC higher than the stoichiometry (nDMC/nSn(cat) = 1.5). In addition, the solid state structures of [BnNMe3]+[CB11H12]- (6) and [(n-Bu)20Sn10O2(OMe)6(CO3)2]2+·2[CB11H12]- (7), isolated as single-crystals and resulting from the recombination of 4 under the reaction conditions (methanol/CO2), were established by sc-XRD analyses within the term of this work as well. 6 and 7 were also fully characterized by IR spectroscopy, multinuclear NMR in solution and elemental analysis.
Zn/Fe mixed oxide: Heterogeneous catalyst for the synthesis of dimethyl carbonate from methyl carbamate and methanol
Wang, Dengfeng,Zhang, Xuelan,Gao, Yangyan,Xiao, Fukui,Wei, Wei,Sun, Yuhan
, p. 430 - 433 (2010)
A series of Zn-Fe-O mixed oxides were prepared for the synthesis of dimethyl carbonate (DMC) from methyl carbamate and methanol. X-ray diffraction revealed that zinc ferrite crystal phase appeared and changed with different Zn/Fe molar ratio. The DMC yield could reach 30.7% under suitable conditions. In addition, elemental chemical analysis and the reusability test indicated that these catalysts presented good stability.
Graphene oxide supported molybdenum cluster: First heterogenized homogeneous catalyst for the synthesis of dimethylcarbonate from CO2and methanol
Kumar, Subodh,Khatri, Om P.,Cordier, St??phane,Boukherroub, Rabah,Jain, Suman L.
, p. 3488 - 3494 (2015)
The octahedral molybdenum cluster-based compound, Cs2Mo6Bri8Bra6 was immobilized on graphene oxide (GO) by using a facile approach. High resolution transmission electron microscopy results revealed that molybdenum clusters were uniformly distributed on the GO nanosheets. Cs2Mo6Bri8Bra6 was attached to the GO support via chemical interaction between apical ligands of Mo6Bri8Bra6 cluster units and oxygen functionalities of GO, as revealed by XPS studies. The developed material was used for the synthesis of dimethyl carbonate by reduction of carbon dioxide. The synthesized catalyst, that is, GO-Cs2Mo6Bri8Brax, exhibited higher catalytic efficiency than its homogeneous analogue without using dehydrating agent. The catalyst was found to be efficiently recyclable without significant loss of catalytic activity.
Preparation and characterization of H3PW12O40/ZrO2 catalyst for carbonation of methanol into dimethyl carbonate
Chiang, Chao Lung,Lin, Kuen Song,Yu, Ssu-Han
, p. 3797 - 3811 (2018)
A H3PW12O40/ZrO2 catalyst for effective dimethyl carbonate (DMC) formation via methanol carbonation was prepared using the sol–gel method. X-ray photoelectron spectra showed that reactive and dominant (63%) W(VI) species, in WO3 or H2WO4, enhanced the catalytic performances of the supported ZrO2. The mesoporous structure of H3PW12O40/ZrO2 was identified by nitrogen adsorption–desorption isotherms. In particular, partial sintering of catalyst particles in the duration of methanol carbonation caused a decrease in the Brunauer–Emmett–Teller surface area of the catalyst from 39 to 19?m2/g. The strong acidity of H3PW12O40/ZrO2 was confirmed by the desorption peak observed at 415?°C in NH3 temperature-programmed desorption curve. At various reaction temperatures (T = 110, 170, and 220?°C) and CO2/N2 volumetric flow rate ratios (CO2/N2 = 1/4, 1/7, and 1/9), the calculated catalytic performances showed that the optimal methanol conversion, DMC selectivity, and DMC yield were 4.45, 89.93, and 4.00%, respectively, when T = 170?°C and CO2/N2 = 1/7. Furthermore, linear regression of the pseudo-first-order model and Arrhenius equation deduced the optimal rate constant (4.24 × 10?3?min?1) and activation energy (Ea = 15.54?kJ/mol) at 170?°C with CO2/N2 = 1/7 which were favorable for DMC formation.
Synthesis of dimethyl carbonate from methyl carbamate and methanol catalyzed by mixed oxides from hydrotalcite-like compounds
Wang, Dengfeng,Zhang, Xuelan,Zhao, Wenbo,Peng, Weicai,Zhao, Ning,Xiao, Fukui,Wei, Wei,Sun, Yuhan
, p. 427 - 430 (2010)
A series of mixed oxides calcined from hydrotalcite-like compounds with different cations were prepared and their catalytic activities were studied by the synthesis of dimethyl carbonate (DMC) from methyl carbamate and methanol. Among them, ZnFe mixed oxide possessed the best catalytic ability. Furthermore, the zinc-based mixed oxides as well as the corresponding hydrotalcite-like compounds were characterized by using ICP, TGA, CO2-TPD and N2 adsorption/desorption techniques.
Reaction of dibutyltin oxide with methanol under CO2 pressure relevant to catalytic dimethyl carbonate synthesis
Kohno, Kazufumi,Choi, Jun-Chul,Ohshima, Yoshihiro,Yili, Abulimiti,Yasuda, Hiroyuki,Sakakura, Toshiyasu
, p. 1389 - 1392 (2008)
Dibutyltin oxide (Bu2SnO)n (3) reacts with methanol to give the tetrabutyl(dimethoxy)stannoxane dimer (4). The presence of 2,2-dimethoxypropane under a CO2 pressure accelerates the reaction resulting in nearly quantitative yield. Complex 4 exhibits catalytic activity as high as that of {Bu2Sn(OMe)2}2 (1) in the dimethyl carbonate (DMC) synthesis from CO2 and methanol. These results indicate that the conversion of 3 to 4 occurs under catalytic DMC production conditions.
Effects of Mo promoters on the Cu-Fe bimetal catalysts for the DMC formation from CO2 and methanol
Zhou, Ying-Jie,Xiao, Min,Wang, Shuan-Jin,Han, Dong-Mei,Lu, Yi-Xin,Meng, Yue-Zhong
, p. 307 - 310 (2013)
The Mo-promoted Cu-Fe bimetal catalysts were prepared and used for the formation of dimethyl carbonate (DMC) from CO2 and methanol. The catalysts were characterized by X-ray diffraction (XRD), temperature programmed reduction (TPR), laser Raman spectra (LRS), energy dispersive spectroscopy (EDS) and temperature programmed desorption (TPD) techniques. The experimental results demonstrated that the Mo promoters can decrease the reducibility and increase the dispersion of Cu-Fe clusters. The concentration balance of base-acid sites can be readily adjusted by changing the Mo content. The moderate concentration balance of acid and base sites was in favor of the DMC formation. Under optimal experimental conditions, the highest methanol conversion of 6.99% with a DMC selectivity of 87.7% can be obtained when 2.5 wt% of Mo was loaded.
Graphene oxide immobilized copper phthalocyanine tetrasulphonamide: The first heterogenized homogeneous catalyst for dimethylcarbonate synthesis from CO2 and methanol
Kumar, Subodh,Kumar, Pawan,Jain, Suman L.
, p. 18861 - 18866 (2014)
The first successful synthesis of DMC directly from methanol and carbon dioxide using a heterogenized homogeneous graphene oxide immobilized copper phthalocyanine tetrasulphonamide catalyst in the presence of N,N′-dicyclohexylcarbodiimide (DCC) as a dehydrating agent is described. The presence of a dehydrating agent was found to be vital and in its absence the yield of DMC was found to be decreased significantly. Under the optimized reaction conditions, the maximum yield of DMC reaches up to 13.3%. Although the homogeneous copper phthalocyanine tetrasulphonamide catalyst provided a little higher yield of DMC (14.2%), the facile recovery and recycling ability of the heterogeneous catalyst make the developed method more attractive from environmental and economical viewpoints.
