The remarkable effect of the preparation procedure on the catalytic activity of CoBEA zeolites in the Fischer-Tropsch Synthesis. Microporous and Mesoporous Materials, Elsevier, 2015, 211, pp.9-18.
AbstractThis work deals with the investigation of the influence of the preparation procedure and Co content on the activity of CoBEA zeolite in Fischer -Tropsch synthesis. For this purpose the Co-containing zeolites were prepared by a conventional wet impregnation (Co x AlBEA series) and a two-step postsynthesis method (Co x SiBEA series). Calcination at 500 °C, for 3h in air and then reduction at 500 °C in flow of 95 % H 2 -5 % Ar stream of as prepared Co x AlBEA and Co x SiBEA zeolites led to obtain Red-C-Co x AlBEA and Red-C-Co x SiBEA catalysts with different properties in Fischer -Tropsch reaction. The most active catalysts were Red-C-Co 10 SiBEA and Red-C-Co 20 SiBEA with high CO conversion of 90 -95 % and selectivity towards liquid products of 85 % containing C 7 -C 18 n-alkanes, isoalkanes and small amount of olefins. In the case of Red-C-Co x AlBEA catalysts the CO conversion was of 68 % and selectivity towards liquid products of 57 %. The identified liquid products were mainly C 7 -C 16 n-alkanes. Moreover, Red-C-Co x SiBEA catalysts demonstrated better stability and resistance to coke formation than Red-C-Co x AlBEA ones. It is probably related to higher dispersion of cobalt nanoparticles in Red-C-Co x SiBEA than in Red-C-Co x AlBEA catalysts and absence of strong Brønsted acidic sites in the former after removal of aluminium in the first step of two-step postsynthesis preparation procedure.