Activated Carbon‐Supported Mo‐Co‐K Sulfide Catalysts for Synthesizing Higher Alcohols from CO₂

Abstract

Activated carbon-supported Mo-Co-K sulfide catalysts, prepared by stepwise impregnation, were used in the synthesis of higher alcohols via CO 2 hydrogenation. The catalysts with varying Mo contents and defined K/Mo and Co/Mo molar ratios exhibited relatively high CO 2 conversions and high selectivity to total alcohols and C 2+ alcohols. Moreover, the influence of calcination conditions on the sulfidation states and catalytic performance was studied. The surface sulfur runoff of the supported catalysts can be effectively suppressed by online calcination. As a result, the selectivity to total alcohols and C 2+ alcohols can be improved.

Catalysts design for higher alcohols synthesis by CO2 hydrogenation: Trends and future perspectives

“…The addition of KCl was found to increase the rate of alcohol and hydrocarbon formation from 26.4 to 34.1 × 10 − 2 mmol g cat − 1 h − 1 (carbon-based) with the selectivity to C 2+ alcohols (CO free) increasing from 2.8 % to 64.9 %. Furthermore, the positive effects of K as promoter were also observed for Co-Mo oxide and Co-Mo sulfide systems [142,143,162]. The addition of K to β-CoMoO 4 and α-CoMoO 4 by mechanically mixing led to a decrease in CO 2 conversion, though enhanced production of alcohols together with a higher ethanol selectivity (CO free) compared to catalyst without K addition (Fig.…”

“…At these conditions, relatively high selectivity to methanol (about 53 %) and ethanol (16 %) was obtained. Additionally, MoS 2 /AC mainly produced CO and hydrocarbons with a low amount of C 2+ alcohols [142]. Thus, it can be concluded that Mo-based materials alone are not efficient for HAS.…”

“…17). Besides, the addition of K to (Co)Mo sulfide shifts the main products from hydrocarbons to CO and alcohols resulting in a higher selectivity (CO free) to alcohols and C 2+ alcohols [142,162].…”

A Multi‐Parametric Catalyst Screening for CO2 Hydrogenation to Ethanol

“…Pt-Co 3 O 4 , FeRh-based catalysts, CoMo oxides and sulfides, and mixed CuFeZn oxides are only a few examples. [27][28][29][30][31][32][33][34][35][36][37] Their ability to combine rWGS (reverse water-gas shift) and FTS drives the hydrogenation of CO 2 into C 2 + alcohols. The FT functionality does not only enable chain growth but also competes with ethanol synthesis by producing C 2 + hydrocarbons.…”

“…When it comes to classical heterogeneous catalysts, the best performing C 2+ alcohol synthesis catalysts are typically composed of first row transition metal oxides/sulfides or supported noble metals. Pt‐Co 3 O 4 , FeRh‐based catalysts, CoMo oxides and sulfides, and mixed CuFeZn oxides are only a few examples [27–37] . Their ability to combine rWGS (reverse water‐gas shift) and FTS drives the hydrogenation of CO 2 into C 2+ alcohols.…”