Highly Efficient ZIF-67-Derived PtCo Alloy-CN Interface for Low-Temperature Aqueous-Phase Fischer-Tropsch Synthesis

Designing new materials for selective Fischer-Tropsch synthesis (FTS) is an elegant way to enhance local feedstock utilization like biomass and waste. In this approach, we have designed a thermally and chemically stable bimetallic PtCo/NC hybrid nanocomposite catalyst derived from a zeolitic imidazolate framework (ZIF-67, which contains cobalt as a metal center) through carbonization for low-temperature (413-473 K) aqueous-phase Fischer-Tropsch synthesis (AFTS). The selectivity of the desired range of hydrocarbons is adjusted using a highly dispersed PtCo bimetallic alloy, which facilitates extraordinary reduction of a metal oxide to active species by the synergic effect under the AFTS reaction conditions. The ZIF-derived catalyst tested in this study exhibited the highest activity to date for very low temperatures (433 K) in aqueous-phase Fischer-Tropsch synthesis with CO conversion rates between 0.61 and 1.20 mol_CO·mol_Co^-1·h^-1. Insights of the remarkable catalyst activity were examined by in situ X-ray photoelectron spectroscopy (XPS) studies corroborated by density functional theory (DFT) calculation. The bimetallic Co₃Pt (111) surface was found to be highly active for the C-C coupling reaction between surface-adsorbed C and CO, forming a CCO intermediate with a very low activation barrier (E_a = 0.37 eV), in comparison to the C-C coupling activation barrier obtained over the Co (111) surface (E_a = 0.87 eV). This unique approach and observations create a new path for developing next-generation advanced catalyst systems and processes for selective low-temperature FTS.

Application of magnetic field to CO hydrogenation using a confined-space catalyst: effect on reactant gas diffusivity and reactivity

An external magnetic field has recently been applied in reaction processes to promote movement and avoid agglomeration of magnetic particles, and also reduce the activation energy through improving the gas-solid contact. In this work, the effect of an external magnetic field on reactant gas diffusivity and reactivity in CO hydrogenation within a confined-space catalyst was investigated for the first time using a conventional reactor packed with a bimetallic 5Fe-5Co/ZSM-5 molecular sieve catalyst. The synergistic effect between magnetic field and limited mass transfer within zeolite cavities improved the mass transfer ability and reaction phenomena of the reactant molecules, leading to enhancement of catalytic activity with tailored reaction pathways. As a result, CO conversion and CH4 selectivity were increased by factors of 1.9 and 1.3 compared to those without a magnetic field. These synergistic interactions are able to provide an innovative challenge for green and sustainable chemical processes and separation processes by means of selective reactant and product mass transfer designed for selective catalytic conversion in the future.

Fe2O3 hollow microspheres as highly selective catalysts for the production of α-olefins

Fe₂O₃ derived from Fe-glycerate with different interior structures and tunable pore sizes distinctly optimized the product selectivity.

Effect of hierarchical meso–macroporous structures on the catalytic performance of silica supported cobalt catalysts for Fischer–Tropsch synthesis

A series of meso–macroporous silica supports with the same macroporous diameter but different mesoporous diameters were prepared by introducing phase separation into a sol–gel process and used to prepare cobalt catalysts for Fischer–Tropsch synthesis.

Effects of Co/Ce molar ratio and operating temperature on nanocatalyst performance in the Fischer–Tropsch synthesis

The effect of Co/Ce molar ratios on the catalytic performance in FTS.

Pt–CeO2 nanoporous spheres – an excellent catalyst for partial oxidation of methane: effect of the bimodal pore structure

Bimodal pore size distribution played the most important role for the catalyst's superior activity during POM.

Effects of macropores on reducing internal diffusion limitations in Fischer–Tropsch synthesis using a hierarchical cobalt catalyst

Internal diffusion limitations in Fischer–Tropsch catalysts strongly affects their catalytic activities and product selectivities.

Ni nanocluster on modified CeO2–ZrO2 nanoporous composite for tri-reforming of methane

Modified Ni-CeO₂–ZrO₂ nanoporous catalysts have been synthesized by using a very facile solvothermal approach and urea deposition precipitation method. The catalyst system is highly stable for more than 100 h with almost a constant syngas ratio of 2.1 and >95% methane conversion at 800 °C in the tri-reforming reaction of methane.

Silicon carbide supported cobalt for Fischer–Tropsch synthesis: probing into the cause of the intrinsic excellent catalytic performance

The Si_xO_y layer on the surface of SiC plays a great role in the intrinsic excellent catalytic performance of Co/SiC.