A Crystalline Catalyst Based on a Porous Metal‐Organic Framework and 12‐Tungstosilicic Acid: Particle Size Control by Hydrothermal Synthesis for the Formation of Dimethyl Ether

Abstract

Abstract:The strategy for obtaining a crystalline catalyst based on a porous copper-based metal-organic framework and 12-tungstosilicic acid with different particle sizes is reported. Through the control of hydrothermal synthesis and some simple treatments, catalyst samples with average particle diameters of 23, 105, and 450 mm, respectively, were prepared. This crystal catalyst has both the Brønsted acidity of 12-tungstosilicic acid and the Lewis acidity of the copper-based metal-organic framework, and has high density of accessible acid sites. Its catalytic activity was fully assessed in the dehydration of methanol to dimethyl ether. The effect of particle size on the catalytic activity of catalyst was studied, in order to select the particle size appropriate for avoiding the diffusion limitation in heterogeneous gas-phase catalysis. In the selective dehydration of methanol to dimethyl ether, this catalyst exhibited higher catalytic activity than the copper-based metal-organic framework, g-alumina, and g-alumina-supported 12-tungstosilicic acid catalysts. It showed high catalytic performances, even at higher space velocity or in the presence of excess water. In addition, the catalyst was also preliminarily assessed in the formation of ethyl acetate from acetic acid and ethylene. It also exhibited a high activity which was comparable with that of silica-supported 12-tungstosilicic acid catalyst.

The performance of chemically and physically modified local kaolinite in methanol dehydration to dimethyl ether

“…The reaction temperature ranged from 200 to 500°C and the catalyst weight is 2.5 g. The reaction products were analyzed on a gas liquid chromatograph (Hewlett Packard-5890) equipped with FID detector and connected with Carbowax backed column. 4 and is shown in Fig. 1.…”

“…Dimethyl ether (DME) is of interest in the production of clean fuel, as a chemical intermediate for the preparation of many important chemicals, such as dimethyl sulfate and high-value oxygenated compounds [1][2][3][4][5]. Its physical properties are similar to those of liquefied petroleum gas (LPG), so it is used as a replace or a blend-stock with LPG for home heating and cooking [6,7] and also considered as an alternative for diesel fuel.…”

POM@MOF Hybrids: Synthesis and Applications

“…In addition to this, no deactivation of the acid sites by water was observed and no leaching of the POM was noted up to at least 15 cycles. Later on, the same group reported the use of POMs as templates for the construction of novel hybrid compounds, for which the properties of the POM could be tailored towards a specific application [123][124][125]. One of these targeted applications was the adsorption and subsequent hydrolysis of the nerve gas dimethyl methylphosphate to methyl alcohol, for which the conversion increased up to 93% when the temperature was raised to 50 • C [123].…”

Heterogeneous Catalysis of Polyoxometalate Based Organic–Inorganic Hybrids

“…The catalytic activity of NENU-1a was further assessed by the dehydration of methanol to dimethyl ether [ 40 ]. A series of NENU-1a were isolated by the hydrothermal reaction of copper salt, BTC, and [SiW 12 O 40 ] 4− polyoxoanion.…”