Intrinsic Kinetics of Dimethyl Ether Synthesis from Plasma Activation of CO₂ Hydrogenation over Cu–Fe–Ce/HZSM‐5

Abstract

CO is activated in a plasma reactor followed by hydrogenation over a Cu-Fe-Ce/HZSM-5 catalyst, and the intrinsic kinetics of the plasma catalytic process are studied. Compared with CO hydrogenation using Cu-Fe-Ce/HZSM-5 alone, the CO conversion and the dimethyl ether selectivity for the plasma catalytic process are increased by 16.3 %, and 10.1 %, respectively, indicating that the CO was activated by the plasma to promote hydrogenation. A study of the intrinsic kinetics shows that the activation energies of methanol formation, the reverse water-gas shift reaction, and methanol dehydration to dimethyl ether are 149.34, 75.47, and 73.18 kJ mol , respectively, which are lower than if Cu-Fe-Ce/HZSM-5 is used without plasma, indicating that the activation of CO in the plasma reduces the activation energy of the hydrogenation reaction and improves the yield of dimethyl ether.

AgI/TMG‐Promoted Cascade Reaction of Propargyl Alcohols, Carbon Dioxide, and 2‐Aminoethanols to 2‐Oxazolidinones

“…Notably,t he anion did not have significant influence on the reaction outcome. To promote the efficiency, several organic and inorganic bases such as TMG, DBU, DBN (1,5-diazabicyclo[4.3.0]non-5-ene), 2,2'-bipy (2,2'-bipyridine), TMEDA (N,N,N',N'-tetramethylethylenediamine), K 2 CO 3 and TBD (2,3,4,6,7,8-hexaydro-1H-pyrimido[1,2-a]pyrimidine), were evaluated in the presence of Ag 2 O( entries [5][6][7][8][9][10][11]. The strong organic base TMG gave the most promising result with 30 %y ield of 3a (entry 5).…”

“…To our delight, glycols (1h-1j), insteado fa minoa lcohols, were also effective to afford cyclic carbonates in high yields (3h-3j)( entries 8-10). In addition, propargyl alcohols with alkyl or phenyl substituents at the propargylic position (2b-2d)w ere demonstrated to be credible substrates to give the corresponding 2oxazolidinone 3a and a-hydroxyl ketones (4b-4d)i nm oderate to good yields (entries [11][12][13]. To our surprise, for ethisterone (2e), an atural product containing propargyl alcohol motifs, the Ag 2 O/TMG system was still effective to produce the corresponding a-hydroxyl ketone( 4e)i n6 3% yield with no interference to the chiral and other functional groups (entry 14).…”

“…K 2 CO 3 and TBD (2,3,4,6,7,8-hexaydro-1H-pyrimido[1,2-a]pyrimidine), were evaluated in the presence of Ag 2 O( entries [5][6][7][8][9][10][11]. The strong organic base TMG gave the most promising result with 30 %y ield of 3a (entry 5).…”

“…However, the thermodynamic limitation in the condensation reaction of amino alcohols with CO 2 represents am ajor hurdle. On the other hand, because CO 2 is highly stable and difficult to activate, [11] the TON (turnover number) [9a] and TOF (turnover frequency) [9b] of the reactiona re urgently required to improve. To address this issue, we have recently developed an ovel access to 2-oxazolidinonesa nd a-hydroxyl ketones promoted by Ag 2 CO 3 /xantphos as shown in Scheme 1, [12] along with the simultaneous formation of a-hydroxyl ketones,w hich also are of great importance as synthetic intermediates.…”

Mn Modified Ni/Bentonite for CO2 Methanation

“…With the development of modern society and the increasing combustion of fossil fuels, the CO 2 concentration in the atmosphere has increased in recent years, causing global warming and even climate change [1,2]. Hence, CO 2 capture and sequestration (CCS) and conversion continue to play a key role in reducing the atmospheric CO 2 concentration and make the transition towards green energy smoother, especially in carbon-intensive regions [3][4][5][6].…”