Effect of KCoMoS2 Catalyst Structures on the Catalytic Performance of Higher Alcohols Synthesis via CO Hydrogenation

Abstract

Different structures of cobalt and potassium modified molybdenum sulfide catalyst (KCoMoS2) were synthesized by hydrothermal synthesis, coprecipitation and reverse microemulsion methods. Nitrogen adsorption, XRD, TEM, XPS and HAADF-STEM-EDS techniques were used to characterize the catalysts structures. The results indicate that the molybdenum sulfide-based catalyst synthesized by the reverse microemulsion method possessed less sheets with small lateral dimensions, while the catalysts prepared by the former two methods contained a higher number of stacking MoS2 layers. In the test of higher alcohol synthesis from CO hydrogenation, it was found that the catalyst synthesized by the reverse microemulsion method exhibited the best CO conversion and C2+OH selectivity among the prepared catalysts. The correlation study between the catalysts structure and the reaction properties implies that the shorter and thinner molybdenum sulfide sheet structure favored for the exposure of the active sites, which, in turn, brought about an enhanced CO conversion and more C2+OH formation.

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

“…The results reported in Figure c emphasize the results reported by Liu et al and Qin et al: a negative correlation between small average crystallite length ( L̅ < 6 nm) and CO conversion was reported, but the yield of hydrocarbons was relatively higher compared with other catalysts. Altogether, HAS progresses not only via carbon monoxide insertion but also via aldol condensation of shorter alcohols …”

“…Based on the described model, the performance of different active sites on the bulk MoS 2based catalysts for production of hydrocarbons increased in the order basal sites ≪ edge sites < rim sites. They reported that The results reported in Figure 10c emphasize the results reported by Liu et al 70 and Qin et al: 71 a negative correlation between small average crystallite length (L̅ < 6 nm) and CO conversion was reported, but the yield of hydrocarbons was relatively higher compared with other catalysts. Altogether, HAS progresses not only via carbon monoxide insertion but also via aldol condensation of shorter alcohols.…”

“…https://doi.org/10.1021/acs.energyfuels.4c00590Energy Fuels 2024, 38, 8103−8123 the highest catalytic performances over the bulk molybdenum disulfide with smallest particles were attributed to the highest exposure of the rim sites. Noteworthy, the active sites for HAS are increased in the order rim sites < basal sites ≪ edge sites 71. …”