Effect of textural characteristics on the catalytic performance of supported KCoMoS2 in the synthesis of higher alcohols from syngas

Higher Alcohol and Oxygenate Synthesis from Synthesis Gas and Ethanol over Supported K-(Co)MoS2 Catalysts: Effect of Novel Ni-Containing Carbon Nanofiber Supports Formed as Byproducts from Methane Decomposition

“…Secondary C 3+ OH and C 4+ OH were synthesized with small yields (<0.2%) only over KCoMoS 2 /CCA and KCoMoS 2 /CNFS. Otherwise, KCoMoS 2 /Al 2 O 3 shows the highest yield of i- C 4+ OH and i- C 5+ OH because the isomerization reaction takes place on the acid sites of the supported sulfided catalyst, and the alumina-supported KCoMoS 2 catalyst has previously been characterized as a mesoporous catalyst with high acidity as determined by pyridine adsorption (44 mmol/g) …”

“…Otherwise, KCoMoS 2 /Al 2 O 3 shows the highest yield of i-C 4+ OH and i-C 5+ OH because the isomerization reaction takes place on the acid sites of the supported sulfided catalyst, and the alumina-supported KCoMoS 2 catalyst has previously been characterized as a mesoporous catalyst with high acidity as determined by pyridine adsorption (44 mmol/g). 41 The higher yields of C 1+ OH, C 2+ OH, C 3+ OH, and C 4+ OH over KCoMoS 2 /CCA compared with KCoMoS 2 /Al 2 O 3 is attributed to the role of amorphous carbon in decreasing the interaction between alumina and KCoMoS active phase as well as covering the Lewis acid sites of alumina that are favorable for hydrogen spillover. The same behavior has been observed for fiber-activated carbon-supported catalysts (KCoMoS 2 / NWA > KCoMoS 2 /AST) (Figure 11).…”

“…Transmission electron microscopes (TEM) LaB6 Tecnai G2 20F (Thermo Fisher Scientific, Waltham, MA) and TEM FEG Tecnai G2 30F were utilized to analyze the morphology of the fresh catalysts under study dispersed on a continuous micronetted carbon film by manually measuring 350–450 separate crystallites with the Fiji ImageJ software package. The average crystallite length and average stacking were estimated according to refs − . − …”

“…Alumina (γ-Al 2 O 3 ) was crushed and sieved until its particle size was between 0.2 and 0.5 mm. Carbon-covered alumina was prepared using the pyrolysis process according to the method described in ref .…”

“…Catalysts supported on metal oxides (silica, alumina, magnesia, and zirconia) have a lower catalytic performance than those supported on carbon materials. − This can be clarified through the active phase-support interaction; in contrast to metal oxides, the interaction of the active phase with carbon materials is weak. Our research team has put a great deal of effort into examining how novel activated carbon supports affect the (K)­CoMoS active phase for HAS from syngas − and ethanol, , taking into our consideration the attractive characteristics of activated carbons, such as the resistance to basic and acidic condition, porosity, and extremely stability under high pressure and temperatures. In our previous publication, we noticed that the relatively short and thin layers of fiber-activated carbon-supported catalysts enhanced the number of edges and corner sites of MoS 2 -crystallites, which improves the catalytic performances, particularly HAS.…”