Product Distributions of Fischer‐Tropsch Synthesis over Core‐Shell Catalysts: The Effects of Diverse Shell Thickness

Abstract

A series of core-shell catalysts with different shell thickness were synthesized and the effect of microporous silica shell on product distribution of Fischer-Tropsch synthesis was analyzed. Fe 3 O 4 core was prepared by hydrothermal method and the amorphous SiO 2 shell was coated on the Fe 3 O 4 core by sol-gel method. N 2 adsorption-desorption analysis indicated an irregular and microporous silica shell and the pore size distribution moved to smaller diameter with the shell thickness increased. In Fischer-Tropsch synthesis, inactive silica shell increased catalytic activity (FTY) and stability by restricting catalyst cracking and sintering. Product distribution shifted to C 1 -C 4 gaseous hydrocarbons with the increasing shell thickness probably due to the diffusion limitations on reactants/products and structure confinement and separation effect of microporous silica shell on restricting the growth of catalytic active particles. Selectivities of C 5 + were restricted within 10% for core-shell catalysts. WGS reaction activity is reduced as well, which constrains side reaction and amplifies FTS catalytic productivity to hydrocarbons.

LPG Direct Synthesis from Syngas over a Cu/ZnO/ZrO2/Al2O3@H‐β Zeolite Capsule Catalyst Prepared by a Facile Physical Method

“…CO conversion was improved from 40.94 % to 54.8 %. However, about 40 % CO 2 was generated and this was associated to some Water‐Gas‐Shift (WGS) reactions . Catalytic performance results, CO 2 free, have been provided in our Supporting Information Figure S2.…”

Fabrication of a sinter-resistant Fe-MFI zeolite dragonfruit-like catalyst for syngas to aromatics conversion

“…It also implied that even though the Fe oxides are in close contact with the zeolite in the DF structure, the hard-to-reduce Fe species are not formed. The difference in reduction behavior of DF vs FMZ is attributed to the strength of interaction between Fe species and the zeolite [47]. It indicates the interaction between Fe species and zeolite on DF1 is slightly stronger than that of the powdermixing catalyst (FMZ), but significantly weaker than the impregnation catalyst (FSZ).…”

Comparative Studies of Co/SBA‐15 Catalysts Synthesized with Different Silica Sources Including Coal Fly Ash for Fischer‐Tropsch Synthesis

“…The major reactions involved in FTS to generate alkanes (Equation 1), alkenes (Equation 2), and alcohols (Equation 3) are given below. [1][2][3]…”

“…The source of “syngas” can vary from different carbonaceous feedstocks. The major reactions involved in FTS to generate alkanes (Equation 1), alkenes (Equation 2), and alcohols (Equation 3) are given below [1–3] $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr (2n + 1)H_2 + nCO \to C_n H_{2n + 2} + nH_2 O\hfill\cr}}$$$ $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr 2nH_2 + nCO \to C_n H_{2n} + nH_2 O\hfill\cr}}$$$ $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr nCO + (2n)H_2 \to C_n H_{2n + 1} OH + (n - 1)H_2 O\hfill\cr}}$$$ …”