A rational strategy for preparing Cu–ZnO/H-ZSM-5 hybrid catalysts with enhanced stability during the one-step conversion of syngas to dimethyl ether (DME)

2015 ◽  
Vol 493 ◽  
pp. 40-49 ◽  
Author(s):  
Andrés García-Trenco ◽  
Agustín Martínez
2007 ◽  
Vol 115 (1-2) ◽  
pp. 23-26 ◽  
Author(s):  
Youshun Luan ◽  
Hengyong Xu ◽  
Chunying Yu ◽  
Wenzhao Li ◽  
Shoufu Hou

2016 ◽  
Vol 6 (12) ◽  
pp. 4389-4397 ◽  
Author(s):  
A. García-Trenco ◽  
E. R. White ◽  
M. S. P. Shaffer ◽  
C. K. Williams

Colloidal Cu/ZnO nanoparticles combine with γ-Al2O3 to form promising hybrid catalysts for the direct synthesis of dimethyl ether (DME) in liquid phase, showing high activity, selectivity and stability.


2016 ◽  
Vol 683 ◽  
pp. 406-414 ◽  
Author(s):  
Pavel Musich ◽  
Lubov Shilyaeva ◽  
Larisa Kurina ◽  
Alexander Vosmerikov ◽  
Natalia Kosova

The increasing demand for producing dimethyl ether from synthesis gas explains the renewed interest in studying the activity and stability of catalysts. In the present work, resource catalytic testing of ZSM-5 zeolites was carried out in the one-step synthesis of dimethyl ether from synthesis gas for 120 hours. Formation of condensation products was observed on zeolite surface after catalytic tests which leads to lower catalytic activity of samples. Condensation products were investigated by thermal analysis in an oxidizing atmosphere. Textural characteristics of zeolites before and after reaction were investigated. It was shown that methanol significantly contribute to formation of condensation products on the catalyst surface in the process of dimethyl ether production.


Fuel ◽  
2014 ◽  
Vol 121 ◽  
pp. 173-177 ◽  
Author(s):  
Zhuo Li ◽  
Jianqing Li ◽  
Meng Dai ◽  
Yongqiang Liu ◽  
Dezhi Han ◽  
...  

2020 ◽  
Vol 24 (4) ◽  
pp. 465-471 ◽  
Author(s):  
Zita Rádai ◽  
Réka Szabó ◽  
Áron Szigetvári ◽  
Nóra Zsuzsa Kiss ◽  
Zoltán Mucsi ◽  
...  

The phospha-Brook rearrangement of dialkyl 1-aryl-1-hydroxymethylphosphonates (HPs) to the corresponding benzyl phosphates (BPs) has been elaborated under solid-liquid phase transfer catalytic conditions. The best procedure involved the use of triethylbenzylammonium chloride as the catalyst and Cs2CO3 as the base in acetonitrile as the solvent at room temperature. The substrate dependence of the rearrangement has been studied, and the mechanism of the transformation under discussion was explored by quantum chemical calculations. The key intermediate is an oxaphosphirane. The one-pot version starting with the Pudovik reaction has also been developed. The conditions of this tandem transformation were the same, as those for the one-step HP→BP conversion.


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Babacar Faye ◽  
Mouhamed Sarr ◽  
Khaly Bane ◽  
Adjaratou Wakha Aidara ◽  
Seydina Ousmane Niang ◽  
...  

This study evaluated the one-year clinical performance of a one-step, self-etch adhesive (Optibond All-in-One, Kerr, CA, USA) combined with a composite (Herculite XRV Ultra, Kerr Hawe, CA, USA) to restore NCCLs with or without prior acid etching. Restorations performed by the same practitioner were evaluated at baseline and after 3, 6, and 12 months using modified USPHS criteria. At 6 months, the recall rate was 100%. The retention rate was 84.2% for restorations with prior acid etching, but statistically significant differences were observed between baseline and 6 months. Without acid etching, the retention rate was 77%, and no statistically significant difference was noted between 3 and 6 months. Marginal integrity (93.7% with and 87.7% without acid etching) and discoloration (95.3% with and 92.9% without acid etching) were scored as Alpha or Bravo, with better results after acid etching. After one year, the recall rate was 58.06%. Loss of pulp vitality, postoperative sensitivity, or secondary caries were not observed. After one year retention rate was of 90.6% and 76.9% with and without acid conditioning. Optibond All-in-One performs at a satisfactory clinical performance level for restoration of NCCLs after 12 months especially after acid etching.


2021 ◽  
Author(s):  
Dennis Larsen ◽  
Sophie R. Beeren

Template-induced kinetic trapping of specific cyclodextrins in enzyme-mediated dynamic combinatorial libraries of linear and cyclic α-glucans enables the one-step synthesis of cyclodextrins from maltose in water.


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