Study On Mo-Co-K Sulfide-based Catalysts Supported / Promoted By MWCNTs For Mixed Alcohols Synthesis From CO/H₂

The higher alcohols (C₂₊-alcohols) have been considered as one kind of the most important species among coal-based clean synthetic fuels and chemical feedstocks. These C₂₊-oxygenates have been confirmed to be a better and cleaner automobile fuel with high octane number, and lower emissions of NO_x, ozone, CO, and aromatic vapors. Higher alcohol synthesis (simplified as HAS) on MoS2-based catalysts has been extensively studied since the mid-1980s. A number of pioneer works have been published on this subject. Progress in this field has considerably contributed to the growing understanding of the nature of these catalytic reaction systems. Nevertheless, the existing technology of HAS is still on a small scale. The single-pass-conversion of the feed syngas and selectivity to C₂₊-alcohols both were relatively low. Under the used reaction conditions, most systems produce methanol as the main product instead of C₂₊-alcohols. Development of catalysts with high efficiency and selectivity to C₂₊-alcohols has been one of the key objectives for R&D efforts.To the other front, multi-walled carbon-nanotubes (CNTs, simplified as CNTs) have been drawing increasing attention recently. This new form of nanostructured carbon has a much higher degree of structural perfection, and possesses several unique features, such as, highly graphitized tube-wall, nanosized channel and sp²-C-constructed surface. They also display high thermal and electrical conductivity, and excellent performance for adsorption and spillover of hydrogen, which make this kind of nanostructured carbon materials full of promise as a novel catalyst support or promoter.In the present work, the supported or co-precipitated catalysts of Mo-Co-K sulfide based on CNT-based materials or promoted by CNTs were prepared and characterized through a series of physico-chemical techniques, such as TEM/EDX, SEM, XRD XPS, H₂-TPR (temperature-programmed reduction) and H₂(or CO)-TPD (temperature-programmed desorption) measurements. The catalysts displayed higher catalytic activity and selectivity for HAS from syngas, as compared to the reference...