Studies On Cu-Fe-based Catalyst For Conversion Of Syngas To Higher Alcohols

The Si-OH concentration of SiO2 decreases by the treatment of ammonia, which weakened the interaction between the metal and the carrier for Cu-Fe/SiO2-N catalyst and increased the dispersion of the copper. The increase of Cu dispersion resulted in the stronger synergistic effect between Cu and Fe, which greatly increased the adsorption of CO and insertion of CHx to generate CHXCO. In addition, the modified catalyst had the stronger ability of CO dissociation than the unmodified catalyst, which made the catalyst Cu-Fe/SiO2-N exhibit a higher catalytic activity.The SiO2 support was pretreated by different concentrations of ethanediamine (C2H8N2). The catalyst Cu-Fe/SiO2-1 pretreated by 1 mol/L C2H8N2 had the strongest ability for CO adsorption/dissociation and higher dispersion of Cu, resulting in the increased conversion of CO, the selectivity and the highest yield of higher alcohols. With the further increase of C2H8N2 concentration, the catalyst activity decreased.The Cu-Fe catalyst supported on SB A-15 has higher catalytic activity than the corresponding catalyst supported on commercial SiO2. The content of active copper increased with the increase of the Cu/Fe dispersion for the catalyst Cu-Fe/SBA-15, which improved the adsorption of CO. The catalysts prepared by different methods (ultrasonic assisted impregnation, rotary evaporation and traditional impregnation) had no significant difference for the yield of higher alcohol.