Although many researchers have reported CO 2 hydrogenation to various C1 chemicals, it is still challenging to directly and selectively convert CO 2 to C 2 -C 4 hydrocarbons in terms of overcoming the extreme inertness of CO 2 and a high C C coupling barrier. In the present work, we report an efficient integration of methanol-synthesis and the methanol-to-hydrocarbons with the bifunctional catalyst component of In 2 O 3 -ZrO 2 and SAPO-5. These tandem reactions exhibit an excellent relative selectivity of C 2 -C 4 (83%) with a suppressed CH 4 relative selectivity less than 3% at T = 300 °C. A detailed analysis indicates that the partially reduced indium oxide surface (In 2 O 3 -ZrO 2 ) can better activate CO 2 and promote the synthesis of methanol than In 2 O 3 alone, and C C coupling is subsequently manipulated within the confined acidic pores of SAPO-5 according to XRD, H 2 -TPR, CO 2 -TPD, SEM and TEM. Furthermore, the proximity of two components and the content of Si also play an important role in such outstanding selectivity to C 2 -C 4 . Our study paves a new path for the direct synthesis of lower hydrocarbons.
Under the dual pressures of oil depletion and low-carbon transition, Fischer-Tropsch synthesis (FTS) technology offers a viable option for producing high value-added lower (C 2 -C 4 ) hydrocarbons from non-oil sources. However, conventional Fe-based catalysts often suffer from deactivation due to carbon deposition and sintering. Here, we report a unique Fe-ZSM-5 catalyst synthesized by doping Fe into ZSM-5, which demonstrates excellent FTS catalytic performance. During high-temperature template removal, Fe species migrated from the zeolite framework to form highly dispersed FeO x clusters (∼2 nm). Upon treatment by syngas, these FeO x clusters aggregate to form uniformly small-sized Fe 5 C 2 @C core-shell particles distributed on ZSM-5 support. The confinement effect of the inter-crystalline structure effectively prevents the sintering of Fe 5 C 2 . The smaller Fe 5 C 2 particles exhibit controlled CO dissociation, reducing the concentration of activated carbon species (C*), and the carbon shells (∼6.5 nm) limit the departure of C*, effectively suppressing carbon deposition. This unique structure enables stable catalytic activity for over 100 hours with maintained product selectivity. The Fe-ZSM-5 catalyst achieved a C 2 -C 4 hydrocarbons selectivity of 54.52 %, nearing the 56 % theoretical limit of the Anderson-Schulz-Flory (ASF) distribution. Additionally, the hydrophobic carbon shell prevents excessive oxidation of Fe 5 C 2 , reducing CO 2 selectivity by ∼56 % compared to conventional Fe/ZSM-5 catalysts, significantly enhancing atomic utilization efficiency and aligning with the principles of green development.
危险品化学品经营许可证（带存储）