Synthesis and conversion of alcohols over modified transition metal sulphides

Carbon-Supported KCoMoS2 for Alcohol Synthesis from Synthesis Gas

“…The coke content was determined by thermogravimetric analysis (TGA) using a NETZSCH STA 4449 F3 Jupiter apparatus. Thermogravimetric and differential thermogravimetric curves for the CCA were recorded in flowing air from room temperature to 600 • C (heating rate 10 • C/min) [24]. The carbon loading on the CCA support is close to the 1.7% that has been reported to be the optimum loading for alcohol production [25].…”

“…Activated carbons (ACs) have many attractive properties [17,18], such as high stability at high reaction temperatures and pressures [18][19][20], high surface area, both micro and meso porosity, resistance to acidic and basic conditions, and minimal interaction between support and active phase [21,22]. Activated carbon supports show higher activity for syngas conversion than metal oxide supports (Al 2 O 3 , SiO 2 , MgO, and ZrO 2 ) because of the weak interaction between the carbon and KCoMoS active phase and the low acidity compared with metal oxides [23,24]. Therefore, we have studied carbon-supported KCoMoS 2 catalysts for HAS from syngas.…”

Effect of Promoter Nature on Synthesis Gas Conversion to Alcohols over (K)MeMoS2/Al2O3 Catalysts

“…It is commonly accepted [13,[33][34][35] that selectivity in this reaction is calculated in CO 2 free basis approximation. The reason for that is the following: the CO 2 is mainly formed in the course of water gas shift or Boudouard reactions and is considered as by-product does not affecting the selectivity of the target products.…”

Assessing C3–C4 alcohol synthesis pathways over a MgAl oxide supported K/MoS2 catalyst via 13C2-ethanol and 13C2-ethylene co-feeds

“…Early studies over unsupported alkali/MoS 2 and alkali/Co/MoS 2 with a 13 C-methanol co-feed by Santiesteban et al revealed that only preferential enrichment of the terminal carbon of ethanol occurred, suggesting that CO inserted into a methyl intermediate to form an acyl precursor that was hydrogenated to produce ethanol [21]. However, recent studies hypothesized that ethanol self-coupling reactions to 1-butanol may also be important over related catalysts [22][23][24]. Christensen et al observed that the production of 1-butanol was more strongly enhanced than 1-propanol formation with increasing ethanol co-feed over a carbon supported K/Co-MoS 2 catalyst, suggesting that self-coupling of ethanol or ethanol-derived species leads to 1-butanol [23].…”

“…The work of Christensen et al on K/CoMoS 2 and Santos et al on K/MoS 2 catalysts previously suggested that higher alcohol formation proceeded not only through CO insertion, but also via aldol condensation of ethanol to 1-butanol with ethanol and nitrogen (syngas-free) co-feed experiments [23,24]. The caveat of their syngas-free ethanol reaction is that it may be more (or less) likely to facilitate the ethanol self-coupling reaction due to the presence of a nitrogen atmosphere, with the reaction potentially occurring differently in a syngas atmosphere [22]. This observation highlights the importance of this work as the first study to conclusively show evidence for ethanol self-coupling to form 13 C 4 -1-butanol species in a syngas atmosphere over a K/MoS 2 based catalyst.…”