Structure and catalytic activity correlation of CoAlPO4 in the synthesis of N,N-biphenyl urea via alkylation of aniline using dimethyl carbonate

2005 ◽  
Vol 6 (1) ◽  
pp. 29-35 ◽  
Author(s):  
G. Kuriakose ◽  
J.B. Nagy ◽  
N. Nagaraju
Keyword(s):  
Catalytic Activity ◽  
Dimethyl Carbonate

Active Pd(ii) complexes: enhancing catalytic activity by ligand effect for carbonylation of methyl nitrite to dimethyl carbonate

2017 ◽  
Vol 7 (17) ◽  
pp. 3785-3790 ◽  
Author(s):  
Hong-Zi Tan ◽  
Zhi-Qiao Wang ◽  
Zhong-Ning Xu ◽  
Jing Sun ◽  
Zhe-Ning Chen ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Dimethyl Carbonate ◽  
Ligand Effect ◽  
Methyl Nitrite ◽  
Catalytic Activities

The catalytic activities of Pd(ii) complexes for carbonylation of methyl nitrite to dimethyl carbonate could be enhanced by ligand effect.

scholarly journals Gas phase synthesis of dimethyl carbonate from CO2 and CH3OH over Cu-Ni/AC. A kinetic study

2019 ◽  
pp. 88-99 ◽  
Author(s):  
Oscar Felipe Arbeláez-Pérez ◽  
Sara Dominguez Cardozo ◽  
Andrés Felipe Orrego-Romero ◽  
Aida Luz Villa Holguin ◽  
Felipe Bustamante Londoño
Keyword(s):  
Carbon Dioxide ◽  
Catalytic Activity ◽  
Activated Carbon ◽  
Gas Phase ◽  
Dimethyl Carbonate ◽  
Direct Synthesis ◽  
Dispersion Analysis ◽  
Molar Ratio ◽  
Rate Determining Step ◽  
Carbonate Formation

The catalytic activity for dimethyl carbonate formation from carbon dioxide and methanol over mono and bimetallic Cu:Ni supported on activated carbon is presented. Bimetallic catalysts exhibit higher catalytic activity than the monometallic samples, being Cu:Ni-2:1 (molar ratio) the best catalyst; X-Ray diffraction, transmission electron microscopy, and metal dispersion analysis provided insight into the improved activity. In situ FT-IR experiments were conducted to investigate the mechanism of formation of dimethyl carbonate from methanol and carbon dioxide over Cu-Ni:2-1. The kinetics of the direct synthesis of dimethyl carbonate in gas phase over Cu:Ni-2:1 supported on activated carbon catalyst was experimentally investigated at 12 bar and temperatures between 90 oC and 130 oC, varying the partial pressures of CO2 and methanol. Experimental kinetic data were consistent with a Langmuir–Hinshelwood model that included carbon dioxide and methanol adsorption on catalyst actives sites (Cu, Ni and Cu-Ni), and the reaction of adsorbed CO2 with methoxi species as the rate determining step. The estimated apparent activation energy was 94.2 kJ mol-1.

scholarly journals Evolution of the pore and framework structure of NaY zeolite during alkali treatment and its effect on methanol oxidative carbonylation over a CuY catalyst

2020 ◽  
Vol 44 (11-12) ◽  
pp. 710-720
Author(s):  
Lifei Yan ◽  
Tingjun Fu ◽  
Jiajun Wang ◽  
Nilesh Narkhede ◽  
Zhong Li
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Photoelectron Spectroscopy ◽  
Dimethyl Carbonate ◽  
Alkali Treatment ◽  
Oxidative Carbonylation ◽  
Framework Structure ◽  
Y Zeolite ◽  
Cage Structure ◽  
X Ray

Alkali treatment is widely used on aluminosilicate zeolites with high Si/Al ratios in order to fabricate mesopores in the framework. However, for zeolites with low Si/Al ratios, the effect of alkali treatment on the pore and framework structure needed further study. In this work, Y zeolite is treated with NaOH solutions of different concentrations and is used as the support for Cu-based catalysts for oxidative carbonylation of methanol to dimethyl carbonate. The physicochemical properties of the supports and corresponding catalysts are characterized by N2 adsorption–desorption, X-ray diffraction, X-ray fluorescence, transmission electron microscopy, inductively coupled plasma mass spectrometry, X-ray photoelectron spectroscopy, and H2-temperature-programmed reduction analyses. The results show that no obvious mesopores are formed under alkali treatment, even at high NaOH concentration. However, amorphous species present in the micropores of Y zeolite are removed, which increases the micropore surface area as well as the crystallinity. Simultaneously, the cage structure is partially destroyed, which also leads to a slight increase of the pore volume and surface area. The altered micropore structure eventually increases the content and accessibility of the exchanged Cu species, which is beneficial to the catalytic activity. When the concentration of NaOH is 0.6 M, the space time yield of dimethyl carbonate for the corresponding catalyst was 151.4 mg g−1 h−1 which is 3.3-fold higher than that of the untreated-Y-zeolite-supported Cu catalyst. However, further increasing the alkali treatment strength can seriously destroy the basic aluminosilicate structure of the Y zeolite and decrease its intrinsic ion-exchange capacity. This results in the formation of agglomerated CuO on the catalyst surface, which was not conducive to catalytic activity.

Carbon nanotube-supported Cu-based catalysts for oxidative carbonylation of methanol to methyl carbonate: effect of nanotube pore size

2020 ◽  
Vol 10 (8) ◽  
pp. 2615-2626 ◽  
Author(s):  
Dan Zhao ◽  
Guoqiang Zhang ◽  
Lifei Yan ◽  
Lingqi Kong ◽  
Huayan Zheng ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Carbon Nanotube ◽  
Pore Size ◽  
Dimethyl Carbonate ◽  
Oxidative Carbonylation ◽  
Inner Diameter ◽  
Methyl Carbonate

The inner diameter of CNTs significantly affected the location, dispersion, autoreduction and stability of Cu species and thus the catalytic activity and stability for oxidative carbonylation of methanol to dimethyl carbonate.

Influence of surface oxygenated groups on the formation of active Cu species and the catalytic activity of Cu/AC catalyst for the synthesis of dimethyl carbonate

2016 ◽  
Vol 390 ◽  
pp. 68-77 ◽  
Author(s):  
Guoqiang Zhang ◽  
Zhong Li ◽  
Huayan Zheng ◽  
Zhiqiang Hao ◽  
Xia Wang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Dimethyl Carbonate

scholarly journals Application of corncob residue-derived catalyst in the transesterification of glycerol with dimethyl carbonate to synthesize glycerol carbonate

BioResources ◽  
2019 ◽  
Vol 15 (1) ◽  
pp. 142-158 ◽  
Author(s):  
Song Wang ◽  
Jianye Wang ◽  
Patrick U. Okoye ◽  
Shuang Chen ◽  
Xinshu Li ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Structural Investigation ◽  
Dimethyl Carbonate ◽  
Low Cost ◽  
Molar Ratio ◽  
Glycerol Carbonate ◽  
Mineral Salts ◽  
Glycerol Conversion ◽  
Catalyst Amount ◽  
High Basicity

Corncob was calcined within a temperature range of 300 °C to 700 °C to prepare a series of corncob residue catalysts for the transesterification of glycerol with dimethyl carbonate (DMC) to synthesize glycerol carbonate (GC). Among the catalysts, the corncob residue catalyst obtained through calcination of corncob at 500 °C (CCR-500) showed a relatively high basicity and satisfactory catalytic activity. The structural investigation results indicated that CCR-500 was composed of carbon material and some alkaline mineral salts. Using CCR-500 as the catalyst, a glycerol conversion of 98.1% and a GC yield of 94.1% were achieved when the reaction was performed at 80 °C for 90 min, with a catalyst amount of 3 wt% and glycerol to DMC molar ratio of 1:3. The comparison of CCR-500 with the reported catalysts indicated that the CCR-500 was a low-cost, high-active, and easily-accessible catalyst for the transesterification of glycerol with DMC.

Catalytic synthesis of glycol dicarbonate from glycol and dimethyl carbonate by transesterification

2019 ◽  
Vol 43 (5-6) ◽  
pp. 211-216 ◽  
Author(s):  
Ruiyang Chen ◽  
Tong Chen ◽  
Xiaojia Hu ◽  
Youkun Fan ◽  
Gongying Wang
Keyword(s):  
Catalytic Activity ◽  
Dimethyl Carbonate ◽  
Reaction System ◽  
Catalytic Performance ◽  
Catalytic Synthesis ◽  
Catalyst Screening ◽  
Acidic Catalysts ◽  
Medium Strength ◽  
Basic Catalysts

Glycol dicarbonate is successfully synthesized via transesterification of glycol with dimethyl carbonate. A catalyst screening is performed by studying the effect of acidity and alkalinity on the catalytic performance. The results indicate that compared with acidic catalysts, high conversions and yields are obtained with basic catalysts. Ca(OH)2, with medium-strength alkalinity, exhibits excellent catalytic activity with glycol dicarbonate yields of 95%-99% when using a fractionation reaction system.

Lewis acid sites in MOFs supports promoting the catalytic activity and selectivity for CO esterification to dimethyl carbonate

2020 ◽  
Vol 10 (6) ◽  
pp. 1699-1707 ◽  
Author(s):  
Yu-Ping Xu ◽  
Zhi-Qiao Wang ◽  
Hong-Zi Tan ◽  
Kai-Qiang Jing ◽  
Zhong-Ning Xu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Lewis Acid ◽  
Dimethyl Carbonate ◽  
Metal Organic Frameworks ◽  
Acid Sites ◽  
Lewis Acidity ◽  
Catalyst Supports ◽  
Lewis Acid Sites ◽  
Metal Organic

We studied the effect of Lewis acidity in metal–organic frameworks (MOFs) on their activity as catalyst supports for the esterification of CO to dimethyl carbonate.

Activity of ceria and ceria-supported gold nanoparticles for the carbamoylation of aliphatic amines by dimethyl carbonate

2011 ◽  
Vol 84 (3) ◽  
pp. 685-694 ◽  
Author(s):  
Raquel Juárez ◽  
Avelino Corma ◽  
Hermenegildo García
Keyword(s):  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Aromatic Amines ◽  
Au Nanoparticles ◽  
Dimethyl Carbonate ◽  
Aliphatic Amines ◽  
Supported Gold Nanoparticles ◽  
Supported Gold

Aliphatic amines react sluggishly with dimethyl carbonate (DMC) to give a mixture of N-methylation and carbamoylation. Nanoparticulated ceria as catalyst increases, in general, conversion and selectivity toward carbamoylation. This increase in catalytic activity and selectivity toward carbamoylation is even increased by deposition of Au nanoparticles on ceria. However, in contrast to aromatic amines for which a complete selectivity toward carbamoylation using ceria-supported Au nanoparticles can be achieved, the catalytic carbamoylation of aliphatic amines by ceria-supported Au nanoparticles occurs only with moderate selectivity.

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