Effective Inclusion of ZnMg in a Fe-Based/HZSM-5-IntegratedCatalyst for the Direct Synthesis of Aromatics from Syngas

Being a significant raw material to numerouschemicals, aromatic hydrocarbons have been emerged as anadvancing research platform in recent years, via the syngas toaromatics (STA) process. In the current study, a modified FeZnMgcatalyst prepared by a sol-precipitation method was integrated withan HZSM-5 catalyst for the direct aromatic synthesis from syngas.Various catalytic/process parameters, including catalyst loadingamount, precipitating pH, calcination/reduction/reactionT, spacevelocity, syngas ratio, reactionP, and reduction time, contributedtoward the different synergism of the bimetallic Fe oxidenanoparticles. The significant electronic modulations inducedupon the effective inclusion of Zn in a feasible parametric influenceled to the generation of spinel (ZnFe2O4) ferrite that eventuallyfacilitated the reduction process of Fe oxide. While the enhanced dispersion of active sites and tuned Fe-lattice structures with Mgaddition improved the carburization behavior of Fe species in response to the stronger C-O chemisorption, and thereby suppressedthe excessive CO2and C1-C4paraffin generation. The originated synergistic interaction of bimetallic species in an appropriatecatalytic environment of FeZnMg for accelerating the formation of Fe carbide, dictate the 52% aromatic selectivity at 97% COconversion. While an excess in the Zn-Mg loading amount, pH, and calcination/reduction/reaction,T, can adversely affect thecatalytic activity to varying degrees of the diminished active catalyst surface and inhibit CO adsorption.

Automated summary

Aromatic hydrocarbons are important raw materials for chemicals and have become a research focus in recent years. In this study, a modified FeZnMg catalyst was combined with an HZSM-5 catalyst for direct aromatic synthesis from syngas. The addition of Zn improved the reduction process of Fe oxide, while the addition of Mg enhanced the carburization behavior of Fe species. The synergistic interaction of bimetallic species in the FeZnMg catalyst promoted the formation of Fe carbide and achieved high aromatic selectivity.