Promotion Effects of Platinum and Ruthenium on Carbon Nanotube Supported Cobalt Catalysts for Fischer–Tropsch Synthesis

Abstract

Carbon nanotube supported nano-size monometallic and noble metal (Pt and Ru) promoted cobalt catalysts were prepared by incipient wetness impregnation (IWI) using solution of cobalt nitrate and characterized by nitrogen adsorption isotherm, X-ray diffraction (XRD), temperature programmed reduction, in situ magnetic method and TEM. Analysis of the magnetization and H 2 -TPR data suggested promotion with platinum and ruthenium significantly decreased the cobalt species reduction temperature. TEM and XRD results showed that the presence of noble metal promoters had no significant effect on the size of cobalt for carbon naotube as catalytic support. Promotion of cobalt carbon nanotube-supported catalysts with small amounts of Pt and Ru resulted in slight increase in Fischer-Tropsch cobalt time yield. The Pt and Ru promoted cobalt catalyst exhibited carbon monoxide conversion of 37.1 and 31.4, respectively. C 5 ? hydrocarbon selectivity was attained at 80.0%. The Pt promoted cobalt supported on carbon nanotube yielded better catalytic stability than that of the monometallic cobalt catalyst.

Fischer–Tropsch synthesis using Co and Co-Ru bifunctional nanocatalyst supported on carbon nanotube prepared via chemical reduction method

“…Nevertheless, based on the TPR results the Co-Ru/CNT catalysts, particularly C 4 presented a higher reduction degree and the Co 3 O 4 nanoparticle were reduced easier so that it led to intensify the aggregation of cobalt particles during reduction which in turn provided more available Co active sites over CNTs to take part in FT reaction [41,48] . It is necessary to mention that the first peaks (Co 3 O 4 to CoO) for Co-Ru based catalysts supported on CNTs were more than 300 °C in the present study that is in agreement with literatures [42,49,50] . This result could be attributed to hydrogen spillover processes.…”

Effects of manganese and reduction promoters on carbon nanotube supported cobalt catalysts in Fischer–Tropsch synthesis

“…For Pt (0.025 wt%) no change of selectivity and activity was measured. These results are similar to the results obtained by [22,23] (Table 4). The addition of Pt or Ru enhances the reducibility.…”

Heterogeneous Catalysis on Nanostructured Carbon Material Supported Catalysts

“…CNT-supported Pt or Ru promoted cobalt catalysts were also investigated. 181 Promotion with platinum and ruthenium significantly decreased the cobalt species reduction temperature. The presence of noble metal promoters had no significant effect on the size of cobalt nanoparticles.…”