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

Abstract

The influence of the promoter nature and of a modifier in (K)(Me)MoS2/Al2O3 (Me=Fe, Co, Ni) catalysts on the conversion and selectivity of products of synthesis gas conversion to alcohols and jnl oxygenates was investigated. Relationships between promoter nature, hydrocarbon chain length and selectivity in the formed alcohols were established. Electronic structure of a promoter atom in an active site (AS) was found to strongly affect selectivity of alcohol formation. Promotion of the S‐edge by Fe, Co or Ni suppressed hydrogen activation, which resulted in a lower synthesis gas conversion. Promotion of the M‐edge by Fe, Co, or Ni entailed the formation of double vacancies which are active sites of synthesis gas conversion. Potassium affected the oxophilicity of Mo atoms and reduced Co/Ni‐promoted MoS AS. It decreased the probability of C−O bond breaking in the adsorbed intermediate and shifted selectivity from the formation of alkyl towards alkoxide fragments over these catalysts.

Synthesis of Higher Alcohols from Syngas over a K-Modified CoMoS Catalyst Supported on Novel Powder and Fiber Commercial Activated Carbons

“…Enlightened by such a report, we deemed that the lower catalytic performances of Cat-OBC-1 compared with Cat-DAC-1 can be attributed to the agglomeration of the active phase; OBC-1 formed a higher agglomerate compared with DAC (see Figure 1 and Figure S2 ), thus increasing the rim sides and coupling the important sides of HAS (basal, corner, and surface sides). 55 − 57 Figure 5 b revealed that there is no clear correlation between temperature and total liquid yield. Moreover, the KCoMoS 2 catalysts supported powder ACs (Cat-DAC and Cat-OBC-1) yielded more total liquids than fiber ACs (Cat-TCA and Cat-AHM).…”

Sustainable Aviation Fuel from Syngas through Higher Alcohols

“…The primary product according to the carbide mechanism for the higher alcohol formation is an olefin which is rapidly hydrogenated to the corresponding alkane. One important parameter, related to higher alcohols formation from syngas is the chain growth probability, α, which is essential for calculations of the weight fraction of alcohols, W n, [4,5,28,29–31,33,34–37,42,44,48,52] $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr {\rm W}{_{{\rm n}}}/{\rm n}=(1\hbox{-}{\rm \alpha} {^{2}})/{\rm \alpha} {^\ast}{\rm \alpha} {^{{\rm n}}}\ \hfill\cr}}$$$ …”

“…Transformation of syngas to higher alcohols is currently under intensive research [2,4,5,23–57] and several reviews have been published rather recently covering the nature of active centers„ [1,54] and more specifically performance of Fe/Co catalysts and Co carbide nanocatalysts [59] . A simplified reaction scheme for syngas transformation over a bifunctional catalyst is shown in Figure 1 [40] .…”

“…[2] Such higher alcohols are important compounds to be used as fuel additives directly or as feedstock for production of detergents, plastics and lubricants. [3] Higher alcohols as fuel additives increase octane rating of gasoline [4,5] being overall beneficial because of their lower volatility and better solubility in comparison to methanol. In addition, soot and nitrogen oxide formation can be reduced by addition of higher alcohols to gasoline.…”

Synthesis of Methyl Mercaptan on Mesoporous Alumina Prepared with Hydroxysafflor Yellow A as Template: The Synergistic Effect of Potassium and Molybdenum

“…In the field of catalytic synthesis of methanethiol, transition metal sulfides are generally considered to be the main active phase [10,11,14,[17][18][19][20]. Among them, MoS 2 -based catalysts promoted by alkali metals have potential application prospects because of their unique properties, such as sulfur resistance, not ease to coking and avoiding expensive deep desulfurization in industry, which have been also widely used in water-gas shift [21][22][23][24], syngas to higher alcohols [25][26][27][28][29][30], hydrodesulfurization [31][32][33][34] and hydrogenation [35][36][37][38]. The research results of active phase MoS 2 in these fields can also provide some reliable basis for the synthesis of CH 3 SH.…”