Impact of Hydrogenolysis on the Selectivity of the Fischer–Tropsch Synthesis: Diesel Fuel Production over Mesoporous Zeolite‐Y‐Supported Cobalt Nanoparticles

Abstract

Selectivity control is a challenging goal in Fischer–Tropsch (FT) synthesis. Hydrogenolysis is known to occur during FT synthesis, but its impact on product selectivity has been overlooked. Demonstrated herein is that effective control of hydrogenolysis by using mesoporous zeolite Y‐supported cobalt nanoparticles can enhance the diesel fuel selectivity while keeping methane selectivity low. The sizes of the cobalt particles and mesopores are key factors which determine the selectivity both in FT synthesis and in hydrogenolysis of n‐hexadecane, a model compound of heavier hydrocarbons. The diesel fuel selectivity in FT synthesis can reach 60 % with a CH4 selectivity of 5 % over a Na‐type mesoporous Y‐supported cobalt catalyst with medium mean sizes of 8.4 nm (Co particles) and 15 nm (mesopores). These findings offer a new strategy to tune the product selectivity and possible interpretations of the effect of cobalt particle size and the effect of support pore size in FT synthesis.

Synthesis, characterisation, and catalytic evaluation of hierarchical faujasite zeolites: milestones, challenges, and future directions

“…The role of a subsequent acid wash in (e and f) may help to further enhance the catalytic performance. Peng et al 94 recently demonstrated the role of secondary porosity in Fischer-Tropsch catalysis more explicitly. Here, both hierarchical USY and Y zeolites have been evaluated in the form of bi-functional catalysts.…”

“…To address the higher oxygen content in bio oils, Milina et al 90 studied the use of hierarchical faujasites in the acid-catalysed esterification of o-cresol with acetic acid. 94 (d) The yield of cresol acetate (Y CrAc ) in the esterification of acetic acid (AA) with o-cresol as a function of S meso in USY. 16a).…”

“…This can be achieved by either evaluating the properties of hierarchical zeolites using a single method comprising different degrees of mesoporosity (Fig. Although several works have reported the superior performance of bifunctional faujasite catalysts, 21,93,94 the role of external surface in the preparation of bifunctional catalysis is relatively unclear. Especially in studies contacting USY zeolites with CTA + -containing alkaline solutions, such systematic approaches should help to more precisely unravel the relationships between synthesis, properties, and function, crucial to the application-oriented design of hierarchical faujasites (Fig.…”

Reversible Selectivity Modulation of Gasoline and Diesel by a Facile Metal‐Salt‐Modified Fischer–Tropsch Synthesis Strategy

“…To obtain insight into the effects of the metal sulfates on selectivity modulation, one fundamental issue that needed to be addressed first was whether the enhanced selectivity to gasoline in the presence of NiSO 4 was a result of NiSO 4 ‐accelerated hydrocracking/hydrogenolysis of the long‐chain paraffins, which are two major routes shortening the chain length . Hence, we explored the reactivity of n ‐hexadecane ( n ‐C 16 H 34 ) for mimicking long‐chain paraffins on Ru/P25 in the absence of CO under otherwise identical reaction conditions for the AP‐FTS.…”

Fischer–Tropsch Synthesis Bifunctional Catalysts: Cobalt Supported on 3D Mesoporous Cellular Silica Foams Assembled by Using ZSM‐5 Seeds

“…Furthermore, strong interactions between cobalt and pure zeolites usually cause low CO conversions . A recent study has attempted to synthesize large pore Co/zeolite bifunctional catalysts for FTS, such as mesopore/macropore zeolites . These materials provide a more open porous network for the transportation of the reactants in FTS and improve the product selectivity.…”