Preparation of Fischer–Tropsch Supported Cobalt Catalysts Using a New Gas Anti-Solvent Process

Abstract

Cobalt and ruthenium-promoted cobalt Fischer–Tropsch catalysts supported on titania have been prepared for the first time by gas anti-solvent precipitation. The use of dense CO2 as an anti-solvent enables the precipitation of cobalt acetate and ruthenium acetylacetonate onto preformed titania. The gas anti-solvent process produces catalysts with the desired 20 wt % cobalt content as precursors, which on calcination give highly dispersed Co3O4. The addition of ruthenium to the gas anti-solvent prepared cobalt catalysts has been investigated by two methods (a) coprecipitation with cobalt acetate and (b) wet impregnation onto a precalcined cobalt titania catalyst, and these resulted in catalysts with distinctly different properties. These catalysts were compared with a standard ruthenium-promoted cobalt catalyst prepared by wet impregnation and were found to be substantially more active for the Fischer–Tropsch reaction.

UV/Vis Light Induced Degradation of Oxytetracycline Hydrochloride Mediated by Co-TiO2 Nanoparticles

“…In this respect, investigations of the visible light responsivity of TiO 2 have been developed via TiO 2 doping by low amounts of cations [21]; anions [22,23]; and transition metals such as Fe, Cu, Mn, Ni, Cr, Zn, and Co [21][22][23][24][25][26][27]. Among various transition metals (i.e., Pt, Ag, Au, Ru, and Pd) [28][29][30][31] and transition metal oxides (i.e., Cu 2 O, α-Fe 2 O 3 ) [32][33][34], cobalt [35,36] and cobalt oxides [37][38][39][40] as an interesting low-cost and earth-abundant mineral have attracted tremendous attention for the development of visible light active TiO 2 materials. Cobalt-doped TiO 2 photocatalysts have been synthesized by various methods, such as the sol/gel technique [36,[41][42][43][44][45][46][47][48][49][50], hydrothermal treatment [51][52][53][54], impregnation method [55,56], precipitation process [57] for the photocatalytic degradation of methylene blue [57,58], rhodamine B…”

In situ diffraction of highly dispersed supported platinum nanoparticles

“…Such fitting can provide quantitative information on multiphase systems such as phase fractions and structure in addition to microstructural features such as size, strain and defect density which are valuable parameters to determine in order to further catalytic understanding. [7][8][9] XRD of very small (<5 nm), supported nanoparticles is challenging predominantly due to the extremely broad peaks that are produced due to the insufficient number of lattice planes to effectively cancel incoherent scattering at angles close to the Bragg angle. 4,10 The lack of diffraction peaks from metallic phases is sometimes used as evidence that the nanoparticles must be very small or amorphous.…”

Fischer Tropsch Synthesis using promoted cobalt-based catalysts

“…Based on this, it is probably that the shoulders observed in the XRD at an angle of 36.06 • can be assigned to discrete cobalt oxide phases. The second TPR signal observed between 400 and 440 • C (B) can be assigned to the reduction of Co(II) to Co(0) [14,15]. The third signal (C) is attributed to the subsequent reduction of the oxides of manganese [15,16].…”