A kinetic model for Fischer−Tropsch synthesis is derived using a Langmuir−Hinshelwood−Hougen−Watson approach. Experiments were conducted over 25% Co/0.48% Re/Al 2 O 3 catalyst in a 1 L slurry reactor over a range of operating conditions (T = 478, 493, 503 K; P = 1.5, 2.5 MPa; H 2 /CO = 1.4, 2.1; WHSV = 1.0−22.5 NL/(g cat •h)). Rate equations were based on the elementary reactions corresponding to a form of well-known carbide mechanism. The 1-olefin desorption rate constant was assumed to be a function of carbon number due to the effect of weak interaction of the hydrocarbon chain with the catalyst surface. Values of estimated activation energies are in good agreement with those reported previously in the literature. The kinetic model was able to correctly predict all of the major product distribution characteristics, including the increase in chain growth probability and decrease in olefin-to-paraffin ratio with carbon number, as well as formation rates of methane and ethylene.

A review on additive manufacturing (AM) applied to heterogeneous catalysis reveals enabling power of AM and challenges to overcome in chemical interfacing and material printability.

The effect of CO conversion on hydrocarbon selectivities (i.e., CH 4 , C 5? , olefin and paraffin), H 2 /CO usage ratios, CO 2 selectivity, and catalyst stability over a wide range of CO conversion (12-94%) on 0.27%Ru-25%Co/Al 2 O 3 catalyst was studied under the conditions of 220°C, 1.5 MPa, H 2 /CO feed ratio of 2.1 and gas space velocities of 0.3-15 NL/g-cat/h in a 1-L continuously stirred tank reactor (CSTR). Catalyst samples were withdrawn from the CSTR at different CO conversion levels, and Co phases (Co, CoO) in the slurry samples were characterized by XANES, and in the case of the fresh catalysts, EXAFS as well. Ru was responsible for increasing the extent of Co reduction, thus boosting the active site density. At 1%Ru loading, EXAFS indicates that coordination of Ru at the atomic level was virtually solely with Co. It was found that the selectivities to CH 4 , C 5? , and CO 2 on the Co catalyst are functions of CO conversion. At high CO conversions, i.e. above 80%, CH 4 selectivity experienced a change in the trend, and began to increase, and CO 2 selectivity experienced a rapid increase. H 2 /CO usage ratio and olefin content were found to decrease with increasing CO conversion in the range of 12-94%. The observed results are consistent with water reoxidation of Co during FTS at high conversion. XANES spectroscopy of used catalyst samples displayed spectra consistent with the presence of more CoO at higher CO conversion levels.

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