Synthesis and application of CNT-supported MoO3-K2O nanocatalyst using microemulsion technique: role of nanoparticle size on catalyst activity and selectivity in higher alcohol synthesis

Background: Alkalized MoO3 nanocatalyst supported on carbon nanotubes (CNTs) is prepared using microemulsion technique. The nanocatalyst was extensively characterized by different methods, and its activity and selectivity in higher alcohol synthesis (HAS) have been assessed in a fixed bed micro-reactor. The physico-chemical properties and performance of the nanocatalyst were compared with the catalyst prepared by impregnation method. Results: The transmission electron microscopy images showed that small Mo nanoparticles are confined inside the CNTs (1 to 5 nm) and on the outer surface of the CNTs (1 to 7 nm). Using microemulsion technique, the average MoO3 particle sizes decreased from 7 to 4.8 nm, the percentage of dispersion increased from 51 to 59 and the percentage of reduction increased by 37%. Also, the chemical interactions between K-Mo-O species increased, enhancing the conditions for the formation of alcohols. Conclusion: The percentage of CO conversion increased from 27.7% to 43.8%. The hydrocarbon selectivity decreased from 32.4% to 24.5%, and alcohol selectivity increased from 45.3% to 61.4%.