No abstract

Background Ruthenium-promoted cobalt nanocatalysts that are supported by carbon nanotubes (CNTs) are prepared using impregnation and microemulsion techniques. Ruthenium loadings were varied from 0 to 1 wt% while the amount of cobalt was fixed at 15 wt%. The nanocatalysts were extensively characterized by different methods and their activity and selectivity in Fischer-Tropsch synthesis (FTS) have been assessed in a fixed-bed microreactor. The physicochemical properties and performance of the nanocatalysts were compared with the catalyst prepared by impregnation method. Results Very narrow particle size distribution has been produced by the microemulsion technique. According to the transmission electron microscopy, pictures small Co particles (2-7 nm) are mostly confined inside the CNTs. Ruthenium increased the percentage reduction of the unpromoted catalyst by a factor of 25. Compared with the catalysts prepared by impregnation, using microemulsion technique with water-tosurfactant ratio of 0.5 which decreased the average cobalt oxide particle sizes to 4.8 nm, the percentage of dispersion is almost doubled and the percentage of reduction is increased by 28. Conclusions Addition of ruthenium increased the percentage conversion and C 5 ? selectivity of the unpromoted catalyst by a factor of 22.6 and 7, respectively. Activity and selectivity were found to be dependent on the catalyst preparation method and water-to-surfactant ratio (as well as on cobalt particle sizes). The percentage of CO conversion and FTS rate increased from 59.09 to 75.05 and 0.291 to 0.372 g HC/g cat/h, respectively, while the C 5 ? liquid hydrocarbons selectivity decreased slightly.

The corrosion inhibition property of electrochemically synthesized 2,2′-disulfanediyldianiline compound was investigated for mild steel in 1 M HCl using electrochemical and weight loss techniques. The morphology of steel surface was examined using SEM and optical microscopy. Thermodynamic parameters were determined and discussed. To study the effect of the molecular structure of inhibitor on its inhibitive performance, quantum chemical studies were performed using density functional theory by B3LYP/6-311G (d,p) basis set. The theoretical studies depicted -N and -S atoms as the adsorption centers in molecule. Graphical abstract