Selectivity loss in Fischer-Tropsch synthesis: The effect of carbon deposition

Polymeric carbon was deposited over Siralox supported cobalt catalysts by an ethylene treatment at 230 °C and 260 °C. Cobalt with particle sizes of 10 14 nm were studied. Temperature programmed hydrogenation Raman spectroscopy analyses the species found to be similar those formed during Fischer-Tropsch synthesis. The tested in high-throughput 16 parallel reactors 20 bars 220 °C, using a H2/CO ratio 2.12. Data collected different space times compare activities selectivities iso-conversion levels. Ethylene treated showed lower activity that corresponded roughly loss CO adsorption sites. Additionally, decrease heavy products selectivity, increase methane selectivity olefin paraffin observed after treatments. Unlike activity, deselectivation level depend on amount carbon. This phenomenon can explained steric effect deposit, but electronic cannot excluded, is challenging prove.