Effective Suppression of CO Selectivity for CO₂ Hydrogenation to High-Quality Gasoline

Abstract

CO 2 hydrogenation to gasoline fuels remains a sticky problem of CO selectivity from reverse water-gas shift reactions over a metal oxide and zeolite bifunctional catalyst. Herein, we report an efficient catalyst combining a Fe−Zn−Zr−T oxide hydrothermally treated with TPABr solution and HZSM-5 zeolite for CO 2 hydrogenation into high-quality gasoline. The hydrothermal treatment contributes to the obvious enrichment of the Zn component and the residual Br on the surface of Fe−Zn− Zr−T oxide, as compared to Fe−Zn−Zr oxide, as well as the increased number of oxygen vacancies. These surface properties not only induce the increase of the H 2 adsorption and CO 2 adsorption ratio but also enhance the adsorption strength of the HCOO* species and the desorption rate of CH 3 O* species (close intermediate of methanol) over Fe−Zn−Zr−T oxide, which are responsible for higher methanol selectivity and lower CO selectivity. Furthermore, the presence of the adsorbed CO* species and higher C 2+ hydrocarbon selectivity on Fe−Zn−Zr oxide affirm the F−T route of CO 2 hydrogenation except for the methanol route, while the F−T route is effectively restrained after the TPABr hydrothermal treatment of Fe−Zn−Zr−T oxide. As the Fe and Zn−Zr molar ratio decreases, more HCOO* and CH 3 O* species on Fe−Zn−Zr (0.1:1:1)−T−24 h can form, which is in good agreement with the much higher methanol selectivity on Fe−Zn−Zr (0.1:1:1)−T−24 h oxide and hydrocarbon selectivity on the Fe−Zn− Zr(0.

Designing a Multifunctional Catalyst for the Direct Production of Gasoline-Range Isoparaffins from CO2

“…A significant body of literature exists illustrating the advantages of thermochemical multifunctional catalysis (i.e., the combination of a metal/metal oxide and a zeolite as a multifunctional catalyst) for the hydrogenation of CO 2 to useful products. − Chief among the advantages is the sheer tunability of the product distribution that can be achieved by choosing the appropriate components of the multifunctional catalyst. This has repeatedly been demonstrated in the literature with products ranging from light olefins − to aromatics − and paraffins − being obtained by employing complementary configurations of a multifunctional catalyst.…”

Controlling CO2 hydrogenation selectivity by Rh-based catalysts with different crystalline phases of TiO2

“…1 CO 2 capture, storage, and utilization (CCSU) is an effective way to address the change in climate conditions caused by the greenhouse effect. Many high-value chemicals can be obtained by carbon dioxide hydrogenation, such as CO, 2 methane, 3 methanol, 4 high-quality gasoline, 5 and aromatics. 6 Among these, CO 2 methanation and CO 2 hydrogenation to CO, CH 4 , or methanol are considered to be the ideal routes for the utilization of CO 2 , and these simple reaction processes make it easy to explore the initial steps of CO 2 hydrogenation.…”

Direct conversion of CO2 to a jet fuel over CoFe alloy catalysts

“… 1 Therefore, it is imperative to develop processes and technologies for the effective hydrogenation of CO 2 to liquid fuels using renewable hydrogen (H 2 ). Despite some breakthroughs in the synthesis of gasoline (C 5 –C 11 -range hydrocarbons) directly via CO 2 hydrogenation, 2 , 3 , 4 , 5 , 6 there have been few reports on the selective synthesis of jet fuel (C 8 –C 16 -range hydrocarbons). 7 , 8 The traditional approach to the direct synthesis of products with more than two carbons (C 2+ ) through CO 2 hydrogenation involves the carbon monoxide (CO) intermediate formed by cascading the reverse water-gas shift (RWGS) and Fischer-Tropsch synthesis (FTS) reactions.…”