Direct hydrogenation of CO2 to dimethyl ether (DME) over hybrid catalysts containing CuO/ZrO2 as a metallic function and heteropolyacids as an acidic function

Abstract

Dimethyl ether (DME) is considered as a substitution of diesel oil. It can be used in diesel engines because of its high cetane number (> 55). The combustion process does not generate particle matter (PM) or sulphur oxides (SO x) pollutions. One of the methods to obtain DME is direct synthesis from a CO 2 and H 2 mixture. On the other hand, CO 2 is an attractive reagent, which is a safe and economical source of carbon. The aim of this work was to obtain DME in the direct process from the mixture CO 2 and H 2 in the presence of hybrid catalyst. In these catalytic the CuO/ ZrO 2 was selected as a metallic function. The montmorillonite K10 modified by heteropolyacids was selected as an acidic function. The catalysts were obtained by different preparation methods and contained various types of heteropolyacids. The catalysts were characterized by following methods: BET/BJH, XRD, SEM, DCS/ TG, NH 3-TPD and FT-IR. The direct hydrogenation of CO 2 was performed in the high pressure fixed-bed flow reactor connected online with GC equipped with TCD and FID detectors. It was shown that both synthesis method of metallic function and the type of heteropolyacids have influence on the total catalytic activity of the hybrid catalyst. The acidity and thermal stability of HPAs are identified as the most important parameters having a decisive influence on the overall catalytic activity of the samples.

Direct Synthesis of Dimethyl Ether from CO2: Recent Advances in Bifunctional/Hybrid Catalytic Systems

“…The study by Kornas et al [124] examined the effect of the type of HPA (H 3 PW 12 O 40 (HPW) and H 3 PMo 12 O 40 (HPMo) supported on montmorillonite K10 on the activity of the hybrid catalyst combined with CuO/ZrO 2 in the direct CO 2 hydrogenation to DME. Due to the higher acidity of HPW compared to HPMo, the HPW-modified catalyst proved to be more active and stable under the reaction conditions employed than its HPMo-modified counterpart.…”

“…Due to the higher acidity of HPW compared to HPMo, the HPW-modified catalyst proved to be more active and stable under the reaction conditions employed than its HPMo-modified counterpart. The acidity of the catalyst and its thermal stability were the main factors influencing the catalytic activity [124].…”

Increasing dimethyl ether production from biomass-derived syngasviasorption enhanced dimethyl ether synthesis

“…4 The direct synthesis of DME entails the use of two different catalytic phases, one for the synthesis of methanol from syngas and one for DME production. Cu-ZnO-Al 2 O 3 (CZA) materials are the benchmark catalysts for the synthesis of methanol from syngas, 13,16,17 whereas acidic solids such as g-Al 2 O 3 , 16,18 zeolites, 19,20 acidic oxides 21 or heteropolyacids [22][23][24][25] are the most active catalysts for the methanol dehydration to DME.…”

Silica-Related Catalysts for CO2 Transformation into Methanol and Dimethyl Ether

“…Still, the CuFe catalyst is more selective to DME than the CuCo catalyst. More recently, A. Kornas et al [134] have also studied the direct hydrogenation of CO 2 to dimethyl ether with CuO/ZrO 2 catalysts supported on montmorillonite K10 modified with heteropolyacids with Keggin structure (XM 12 O 40 n− ), with X = P and M = W or Mo. The incorporation of metal oxides and heteropolyacids into the K10 clay structure leads to a considerable decrease in the specific surface area, volume and pore size.…”