Mechanistic insights into the catalytic role of various acid sites on ZSM-5 zeolite in the carbonylation of methanol and dimethyl ether

2018 ◽  
Vol 8 (12) ◽  
pp. 3193-3204 ◽  
Author(s):  
Sen Wang ◽  
Shiying Li ◽  
Li Zhang ◽  
Zhangfeng Qin ◽  
Yanyan Chen ◽  
...  
Keyword(s):  
Dimethyl Ether ◽  
Catalytic Performance ◽  
Acid Sites ◽  
Zeolite Framework ◽  
Catalytic Role

The catalytic performance of ZSM-5 in carbonylation is strongly related to the location of acid sites in the zeolite framework.

Study on Preparation and Catalytic Properties of Pd/γ-Al2O3 Catalysts in One-Step Synthesis of Dimethyl Ether

2011 ◽  
Vol 66-68 ◽  
pp. 1404-1409 ◽  
Author(s):  
Rui Zhi Chu ◽  
Zhong Cai Zhang ◽  
Ya Fei Liu ◽  
Xian Liang Meng ◽  
Zhi Min Zong ◽  
...  
Keyword(s):  
Dimethyl Ether ◽  
Catalytic Performance ◽  
Acid Sites ◽  
Co Conversion ◽  
Dimethyl Ether Synthesis ◽  
Acidic Sites ◽  
One Step ◽  
Space Time Yield ◽  
Ether Synthesis ◽  
Synthesis Of Dimethyl Ether

A series of Pd/γ-Al2O3 catalysts with different additons of Pd were prepared by impregnation. The effect of calcination condition and Pd loading on catalytic performance of catalysts for one-step dimethyl ether synthesis has been investigated. The physic-chemical performance and structure of Pd/γ-Al2O3 catalysts were characterized by CO-TPD, TGA and nitrogen physisorption. The results show that the dispersion of Pd and the amount of adsorbration on the CO-bridge of Pd could be increased to by the moderate microwave heating on the catalysts, and the catalyst performance can be improved. But a large number of surface acidic sites of Pd/γ-Al2O3 are covered by highly fragmented Pd-grain, it causes DME selectivity reduced. And the excessive Pd can reduce the samples’ surface acid, decrease the dispersion of the metal Pd and block up the pore of γ-Al2O3. The CO conversion rate and DME space-time yield could reach 60.1% and 28.76 mmol·g-1·h-1 respectively at 2% Pd loading, at this time Pd/γ-Al2O3 has a high Pd activity surface and ideal acid sites.

Methylcyclohexane transformation over H-EU-1 zeolite: Selectivity and catalytic role of the acid sites located at the pore mouths

2008 ◽  
Vol 255 (2) ◽  
pp. 324-334 ◽  
Author(s):  
P MIHINDOUKOUMBA ◽  
J COMPAROT ◽  
S LAFORGE ◽  
P MAGNOUX
Keyword(s):  
Acid Sites ◽  
Catalytic Role

Unravelling the Role of Ceria in Improving the Stability of Mo2C Based Catalyst for Steam Reforming of Dimethyl Ether

2021 ◽  
Author(s):  
Jing-Hong Lian ◽  
Hongyi Tan ◽  
Changqing Guo ◽  
Li-sha Shen ◽  
Zhuo-Xin Lu ◽  
...  
Keyword(s):  
Dimethyl Ether ◽  
Steam Reforming ◽  
Water Oxidation ◽  
Molybdenum Carbide ◽  
Catalytic Performance ◽  
Significant Problem ◽  
The Stability

The inactivation of molybdenum carbide catalyst by water oxidation is a significant problem in steam reforming of dimethyl ether (SRD) reaction. In this work, the catalytic performance and stability of...

Elucidating the nature and role of Cu species in enhanced catalytic carbonylation of dimethyl ether over Cu/H-MOR

2015 ◽  
Vol 5 (9) ◽  
pp. 4378-4389 ◽  
Author(s):  
Huimin Zhan ◽  
Shouying Huang ◽  
Ying Li ◽  
Jing Lv ◽  
Shengping Wang ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Dimethyl Ether ◽  
Methyl Acetate ◽  
Acid Sites ◽  
Bronsted Acid ◽  
Brønsted Acid Sites ◽  
Brönsted Acid ◽  
Brönsted Acid Sites ◽  
Catalytic Carbonylation

The synergistic effect of Cu0 and Brønsted acid sites remarkably facilitates the carbonylation of dimethyl ether to form methyl acetate.

Catalyzed ozonation process with GAC and metal doped-GAC for removing organic pollutants

2004 ◽  
Vol 49 (4) ◽  
pp. 45-49 ◽  
Author(s):  
B.S. Oh ◽  
S.J. Song ◽  
E.T. Lee ◽  
H.J. Oh ◽  
J.W. Kang
Keyword(s):  
Activated Carbon ◽  
Catalyst System ◽  
Catalytic Performance ◽  
Oh Radicals ◽  
Ozone Decomposition ◽  
Depletion Rate ◽  
Catalytic Role ◽  
Ph Conditions ◽  
Metal Doped

The purpose of this study was to investigate the catalytic role of granular activated carbon (GAC), and metal (Mn or Fe) doped-GAC, on the transformation of ozone into more reactive secondary radicals, such as hydroxyl radicals (.OH), for the treatment of wastewater. The GAC doped with Mn showed the highest catalytic performance in terms of ozone decomposition into OH radicals. Likewise, activated carbon alone accelerated the ozone decomposition, resulting in the formation of .OH radicals. In the presence of promoters, the ozone depletion rate was enhanced further by the Mn-GAC catalyst system, even under aqueous acidic pH conditions.

scholarly journals Nitrous Oxide Adsorption and Decomposition on Zeolites and Zeolite-like Materials

Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 398
Author(s):  
Leonid M. Kustov ◽  
Sergey F. Dunaev ◽  
Alexander L. Kustov
Keyword(s):  
Spectroscopic Data ◽  
N2o Decomposition ◽  
Catalytic Performance ◽  
Acid Sites ◽  
Spectroscopic Methods ◽  
Lewis Acid Sites ◽  
Amorphous Systems ◽  
Modified Zeolites ◽  
Mechanism Of The Reaction

Decomposition of N2O on modified zeolites, crystalline titanosilicalites, and related amorphous systems is studied by the catalytic and spectroscopic methods. Zinc-containing HZSM-5 zeolites and titanosilicalites with moderate Ti/Si ratios are shown to exhibit a better catalytic performance in N2O decomposition as compared with conventionally used Cu/HZSM-5 zeolites and amorphous Cu-containing catalysts. Dehydroxylation of the HZSM-5 zeolite by calcination at 1120 K results in an enhancement of the N2O conversion. The mechanism of the reaction and the role of coordinatively unsaturated cations and Lewis acid sites in N2O decomposition are discussed on the basis of the spectroscopic data.

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