Study of Cu-Fe-Co-M/SiO₂ (M = Unpromoted, Li, Na, K and Cs) Catalysts for Mixed Alcohols Synthesis from CO Hydrogenation

Abstract

A series of Cu-Fe-Co based catalysts prepared by co-impregnation method using different alkali additives was characterized by BET, XRD and FESEM-EDX and investigated under MAS from CO hydrogenation. The results showed that the catalyst Cu25Fe22Co3-Na3/SiO2 has the highest catalytic activity and selectivity of total alcohol and C5+OH. XRD and FESEM-EDX demonstrated the Na3 catalyst exhibited homogeneous distribution of elements and effective synergy effect between Cu and Fe components, thereby performed good catalytic performances for MAS from CO hydrogenation. The presence of a suitable content of alkali promoter was necessary for mixed alcohols synthesis from syngas.

Reaction Condition Optimization and Lumped Kinetics Study for Lower Alcohols Synthesis from Syngas Using a Two-Stage Bed Catalyst Combination System

“…The preparation method of Cu 25 Fe 22 Co 3 K 3 catalyst (60−80 mesh, namely 0.180−0.250 mm according to standard ASTM E-11) was described elsewhere. 6 The Cu 4.5 Zn 4.5 Al 1 catalyst was prepared by a two- The flowchart of reaction apparatus is shown in Figure 1. For convenience, the Cu 25 Fe 22 Co 3 K 3 catalyst bed was denoted as CFCK and the Cu 4.5 Zn 4.5 Al 1 catalyst bed was denoted as CZA.…”

“…The preparation method of Cu 25 Fe 22 Co 3 K 3 catalyst (60–80 mesh, namely 0.180–0.250 mm according to standard ASTM E-11) was described elsewhere . The Cu 4.5 Zn 4.5 Al 1 catalyst was prepared by a two-step coprecipitation method.…”

“…5 Furthermore, the introduction of a suitable amount of potassium metal obviously inhibited methane formation and boosted C 2+ alcohols selectivity. 6 At last, under 350 °C, 5.5 MPa and gas hourly space velocity (GHSV) of 6000 h −1 , the catalyst Cu 25 Fe 22 Co 3 K 3 /SiO 2 (simplified as Cu 25 Fe 22 Co 3 K 3 afterward) showed the highest activity of 56.6% and C 2+ alcohols proportion of 79.1 wt % in lower alcohols. However, the CO 2 selectivity is up to 36%, indirectly decreasing the selectivity of total alcohols and C 2+ alcohols.…”

“…In our previous work, a series of Cu–Fe–Co-based catalysts showed higher activity and space–time yield (STY) of lower alcohols than Cu–Fe-based catalyst when little content of the Co component was introduced . Furthermore, the introduction of a suitable amount of potassium metal obviously inhibited methane formation and boosted C 2+ alcohols selectivity . At last, under 350 °C, 5.5 MPa and gas hourly space velocity (GHSV) of 6000 h –1 , the catalyst Cu 25 Fe 22 Co 3 K 3 /SiO 2 (simplified as Cu 25 Fe 22 Co 3 K 3 afterward) showed the highest activity of 56.6% and C 2+ alcohols proportion of 79.1 wt % in lower alcohols.…”