Abstract
Alkali-promoted Ni-Co-Mo catalysts supported on multiwalled carbon nanotubes (MWCNTs) were prepared using 9 wt% K, 4.5 wt% Co, and 15 wt% Mo, whereas Ni content was varied from 0 to 6 wt%. The catalysts were extensively characterized and studied for higher alcohols synthesis from synthesis gas. Alkali-promoted trimetallic catalyst with 3 wt% Ni showed the highest total alcohols yield of 0.284 gm/(gm of cat./h), ethanol selectivity of 20%, and higher alcohols selectivity of 32% at 330°C and 9.0 MPa using gas hourly space velocity (GHSV) of 3.8 m3 (STP)/kg of catalyst/h and H2 to CO molar ratio of 1.25.
Highlights
Ethanol has been used as an additive for reformulated gasoline as unleaded gasoline has become the standard, and short ether compounds (MTBE, ETBE, etc.) have been banned as gasoline octane continues to improve in North America [1]
We have studied the effects of different loadings of active metals (Mo), alkali (K) promoters, and metal promoters (Co and Rh) on higher alcohols synthesis from synthesis gas using K-promoted monometallic, bimetallic, and trimetallic MoS2 catalysts [8, 13, 18, 19]
It was found that total alcohols space time yield (STY) and selectivity were higher on the MWCNTssupported catalyst compared to catalysts supported on activated carbon. These results proved that support pore-size influenced particle size distribution, dispersion, and extent of reduction and plays an important role in diffusing the reactant molecules to the catalytically active centers that are located inside the pores [23]
Summary
Ethanol has been used as an additive for reformulated gasoline as unleaded gasoline has become the standard, and short ether compounds (MTBE, ETBE, etc.) have been banned as gasoline octane continues to improve in North America [1]. Copromotion on alkali-modified MoS2 catalysts leads to the shrinking of MoS2 species, while Co exists mainly in the form of Co-Mo-S phase at low Co loading and partly in a Co9S8-like structure at high Co loading [12] This structural modification leads to the enhanced C1 → C2 homologation step that improves the formation of ethanol as the dominant product [13]. MWCNTs exhibit well-defined hollow interiors and display exceptionally high mechanical strength, thermal stability, and electrical conductivity [21] Their unique characteristics, such as appropriate pore-size distribution, and nanosized channels, make them a promising support in CO hydrogenation reactions [22]. We have compared higher alcohols synthesis from synthesis gas using alkali-promoted trimetallic Co-Rh-Mo-sulfided catalysts that are supported on AC and MWCNTs [19]. A series of MWCNTs-supported Nipromoted catalysts with 9 wt% K, 4.5 wt% Co, and 15 wt% Mo are prepared by varying Ni content from 0 to 6 wt%, and the catalytic performance for higher alcohols synthesis over these catalysts is investigated at optimum operating conditions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
