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Pt/HSSZ-13 with 0.5–3 wt % Pt load and PtCu/HSSZ-13 with 1–7 wt % Cu load were prepared by the initial wetness impregnation method. Without compromising the original crystal structure and surface texture characteristics, doped Pt and Cu are dispersed uniformly throughout the surface. The Si/Al molar ratio affected not only the texture of the crystal but also the number of acid sites on the catalyst surface. The appropriate addition of Cu significantly increased the dispersion of Pt. The addition of Cu also provided electrons to Pt, affected the electron cloud density on the surface of Pt, and then reduced the adsorption of propylene and improved the selectivity of propylene. Cu can also decrease the number of acidic sites on the catalyst surface, thus slowing the deactivation rate of the catalyst and the amount of carbon deposition during the reaction. 1.0Pt3.0Cu/HSSZ-13(40) had a small number of strong acid sites (3.89 µmol/g) and showed the best propane initial conversion (73.95%), excellent propylene selectivity (97.60%), lowest deactivation constant (0.33 h–1), and good regeneration robustness.

The separation of carbon dioxide (CO2) and methane (CH4) in zeolite is significantly influenced by extra-framework cations. Through grand canonical Monte Carlo (GCMC) and molecular dynamics (MD) simulations, the adsorption and diffusion properties of CO2and CH4in diverse M-ZSM-5 zeolites (M = Li, Na, and K) were analyzed. Metal cations, especially at low pressures, enhance the adsorption of CO2. Also, Li-ZSM-5 exhibits the highest CO2loading, followed by Na-ZSM-5 and K-ZSM-5. However, the interaction between CH4and the cations is relatively insignificant. For binary mixtures, CO2dominates the competitive adsorption process. Also, M-ZSM-5 zeolites offer superior adsorption selectivity compared to silicalite-1, with a trend of Li-ZSM-5 > Na-ZSM-5 > K-ZSM-5. Additionally, MD simulations revealed that the metal cations will limit the diffusion of molecules. The combined effect of interaction and spatial constraint induced by cations has a joint influence on the diffusion of CO2, and the self-diffusion coefficients in three models are close.

CO2emission and its conversion to valuable carbon-containing products have attracted increasing attention. In2O3-based catalysts have high selectivity but limited activity for CO2hydrogenation to methanol. To improve the methanol production of In2O3and compare the influence of added cobalt or nickel, two series of In2O3-based catalysts with different Co or Ni mole fractions were synthesized by a co-precipitation method and tested at 240–300 °C, 3 MPa, and GHSV = 7200 mL (gcat−1h−1) to compare their activity and stability. The catalysts were further investigated by XRD, Ar physical adsorption, ICP, XPS, H2-TPR, CO2-TPD, HR-TEM and HAADF-STEM. The results show that adding Co can enhance the reducibility of In2O3but the effect of Ni is in contrast. Abundance of surface oxygen vacancies was not a determining factor for methanol production, and the metal–oxide interface was significant for In2O3catalytic behavior. Adding Ni can significantly improve the CO2conversion (17.63% for Ni10In90and 5.32% for In100at 300 °C and 3 MPa) but lower the methanol selectivity. Ni–In bimetallic species, which have a negative effect on methanol production, can easily form under a reducing and reaction atmosphere. The Co-promoted samples have higher methanol productivity and stability than Ni-promoted samples, with Co20In80having the highest YMeOH, calculated as 5.36% at 280 °C.