Carbon Spheres Prepared by Hydrothermal Synthesis—A Support for Bimetallic Iron Cobalt Fischer–Tropsch Catalysts

Abstract

Carbon spheres (CSs) synthesised by the hydrothermal approach were explored as a model support material for a bimetallic Fe–Co Fischer–Tropsch (FT) catalyst. The CSs were characterised by N2 adsorption–desorption, thermogravimetric analysis, FTIR spectroscopy and powder XRD. If annealed at 900 °C for 4 h, the CSs exhibited an improved surface area, thermal stability and crystallinity. A series of Fe–Co bimetallic FT catalysts supported on the annealed CSs were prepared by co‐precipitation. A variety of Fe‐to‐Co ratios were used with the total metal loadings maintained at 10 %. Catalyst reducibility studies were performed by H2 temperature‐programmed reduction and in situ powder XRD. Catalysts with a Fe/Co ratio of 5:5 (w/w) showed Co–Fe alloy formation upon reduction at >450 °C. Interestingly, the presence of this alloy did not correlate with high C5+ selectivities during FT synthesis; rather the Co‐rich/Fe‐poor catalyst gave the best selectivity. The CSs allowed the metal–metal interactions in the bimetallic systems to be monitored because of the weak interaction of the metals with the support.

Selective CO Methanation Over Ru Supported on Carbon Spheres: The Effect of Carbon Functionalization on the Reverse Water Gas Shift Reaction

“…1a, b) but showed a necklace like accreted conformation. Their surface morphology changed after annealing, consistent with earlier reports by Dlamini and Kumi who showed that the CS surface roughened, due to removal of polymeric species and this led to the opening of the pore structure [33].…”

“…CSs on the other hand are made without the use of a catalyst and so metal purification issues are not a problem. Different facile routes have been established to synthesize CSs, and these include the chemical vapour deposition technique [32] and the hydrothermal technique [33]. Further, the advantages known to be associated when using CNTs and CNFs as catalyst supports such as high surface area and easy surface functionalization apply to CSs as well.…”

“…Herein, we have employed hydrothermally synthesized CSs with known high surface areas and well-structured pores [33] as a catalyst support for Ru in the selective CO methanation reaction. The CS surface was modified by acid treatment (HNO 3 ) which introduced functional groups such as COOH and OH species onto the surface [37,38].…”

Effects of impregnation strategy on structure and performance of bimetallic CoFe/AC catalysts for higher alcohols synthesis from syngas

“…So far, CoFe bimetallic catalysts have been extensively investigated for F-T synthesis [30][31][32][33][34][35][36][37][38][39][40], yet few reports have indicated that these bimetallic catalysts could produce mixed alcohols [30][31][32]. In the present work, the bimetallic CoFe/AC catalysts have been prepared with different impregnation strategies for the F-T synthesis.…”

The Effects of Morphology Re-Arrangements on the Pseudocapacitive Properties of Mesoporous Molybdenum Disulfide (MoS2) Nanoflakes

“…2 and CNS.-First, carbon nanospheres (CNS) were obtained using the established method: 26 In summary, a 0.3 M sucrose solution was transferred into a 100 ml Teflon-lined stainless steel autoclave and heated at 150…”