Recent progress for direct synthesis of dimethyl ether from syngas on the heterogeneous bifunctional hybrid catalysts

2017 ◽  
Vol 217 ◽  
pp. 494-522 ◽  
Author(s):  
K. Saravanan ◽  
Hyungwon Ham ◽  
Noritatsu Tsubaki ◽  
Jong Wook Bae
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.


2015 ◽  
Vol 5 (4) ◽  
pp. 2347-2357 ◽  
Author(s):  
Thongthai Witoon ◽  
Tinnavat Permsirivanich ◽  
Nawapon Kanjanasoontorn ◽  
Chalairat Akkaraphataworn ◽  
Anusorn Seubsai ◽  
...  

Methanol can be dehydrated to form DME over sulfated zirconia catalysts via pathway I, if the sulfur content is low, and pathway II, if the sulfur content is high.


Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1071
Author(s):  
Elena Millán ◽  
Noelia Mota ◽  
Rut Guil-López ◽  
Bárbara Pawelec ◽  
José L. García Fierro ◽  
...  

The performance of bifunctional hybrid catalysts based on phosphotungstic acid (H3PW12O40, HPW) supported on TiO2 combined with Cu-ZnO(Al) catalyst in the direct synthesis of dimethyl ether (DME) from syngas has been investigated. We studied the effect of the HPW loading on TiO2 (from 1.4 to 2.7 monolayers) on the dispersion and acid characteristics of the HPW clusters. When the concentration of the heteropoliacid is slightly higher than the monolayer (1.4 monolayers) the acidity of the clusters is perturbed by the surface of titania, while for concentration higher than 1.7 monolayers results in the formation of three-dimensional HPW nanocrystals with acidity similar to the bulk heteropolyacid. Physical hybridization of supported heteropolyacids with the Cu-ZnO(Al) catalyst modifies both the acid characteristics of the supported heteropolyacids and the copper surface area of the Cu-ZnO(Al) catalyst. Hybridization gives rise to a decrease in the copper surface area and the disappearance of the strong acidic sites typical of HPW nanocrystals, showing all hybrids similar acid sites of weak or medium strength. The activity of the hybrids was tested for direct DME synthesis from syngas at 30 bar and 250 °C; only the hybrids with HPW loading higher than 1.4 monolayers showed activity for the direct synthesis of DME, showing that the sample loaded with 2.7 monolayers of heteropolyacid had higher activity than the reference hybrid representative of the most widely applied catalysts based on the combination of Cu-ZnO(Al) with HZSM-5. In spite of the high activity of the hybrids, they show a moderate loss in the DME production with TOS that denotes some kind of deactivation of the acidity function under reaction conditions.


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