English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Dimethyl ether synthesis was performed from syngas over hybrid catalysts comprising a Cu/Zn/Al as metallic function and K10-montorillonite (K10) as acidic function. The acidic properties of K10 were tuned by deposition of one monolayer of tungstophosphoric acid (H3PW12O40·23.5 H2O, TPA). The changes in acidity were determined based on pyridine adsorption with FTIR detection. Due to the fact that TPA does not possess Lewis acid sites, deposition of TPA on the K10 surface (TPA-K10) resulted only in increase in Brønsted acid site concentrations and in increase in their strength in comparison with unmodified K10. Since both modified and unmodified K10 exhibited the same Lewis acid site concentrations and their strength, it was possible to investigate solely the impact of Brønsted acidity differences of acidic functions on the hybrid catalysts activity in syngas-to-DME process (STD). Additionally, the effect of TPA supported on K10 was investigated in methanol dehydration to DME under atmospheric pressure. In order to prepare metallic functions which differed in activity in CO hydrogenation to methanol (first step of STD), two synthesis methods were used: co-precipitation method (metallic function CZA) and decomposition of citrate complexes of metals (metallic function CZAcitric). The hybrid catalysts (CZA/K10, CZA/TPA-K10, CZAcitric/K10, CZAcitric/TPA-K10) for STD were prepared by physical mixing of metallic and acidic function in volume ratio equal to 2:1. The impact of K10 substitution with TPA-10 in hybrid catalysts depended on whether STD process was controlled by methanol synthesis step or dehydration methanol step. When K10 possessed adequate acidity to dehydrate methanol formed on metallic function (i.e. CZAcitric), it substitution with TPA-K10 in hybrid catalyst did not improve DME yield. On the other hand, when metallic function (i.e. CZA) exhibited higher methanol activity and methanol dehydration rate was limited by insufficient acidity of K10 then usage of TPA-K10 of higher acidity in hybrid catalyst was found to increase significantly DME yield without light parrafins formation.Graphical Abstract

Influence of Montmorillonite K10 Modification with Tungstophosphoric Acid on Hybrid Catalyst Activity in Direct Dimethyl Ether Synthesis from Syngas