Rationally designing NaFeMn/core–shell HZSM-5@Si bifunctional catalyst for selective synthesis of para-Xylene from CO2 hydrogenation

Selective production of aromatics from CO2 hydrogenation has attracted wide attention, but still remains big challenges, especially tuning the selectivity towards value-added p-xylene. Here, an effective NaFeMn/HZSM-5 catalyst was synthesized for selective CO2 hydrogenation to aromatics, over which a high aromatics selectivity of 72 % was realized at 45 % CO2 conversion. It was observed that the co-existence of Na and Mn can generate a beneficial interaction, promoting catalyst reduction and CO2 adsorption. In addition, the selectivity towards benzene-toluene-xylene (BTX) was significantly enhanced from 30 % to 46 % in the presence of organosilicon, by which the structural and acidic properties of the zeolite were improved. Furthermore, when NaFeMn catalyst was combined with core–shell [email protected] zeolite, synthesized by vapor-crystallization, selectivity of p-xylene in xylene was increased from 28 % to 50 %. Compared with traditional hydrothermal treatment, vapor-crystallization endows intact silicalite encapsulation and surface acidity passivation.