A theoretical study on the CO2-ODHP in HZSM-5 zeolite: From the perspective of adsorption and diffusion

[Display omitted] •The ODPH reaction was studied from the perspectives of adsorption and diffusion.•CO2 is more difficult to adsorb in the HZSM-5 pore, but more diffuse.•H2 is difficult to accumulate in the HZSM-5 channels.•The ratio of CO2 to C3H8 approaches 1:1 only when the feed ratio is around 1:3. The oxidative dehydrogenation of propane (ODHP) under the action of CO2 is receiving widespread attention. However, it has not been thoroughly studied in terms of adsorption and diffusion. So, the Monte Carlo and molecular dynamics simulations were used to study the adsorption/diffusion properties of the main reactants and products in HZSM-5. C3H8 has the highest adsorption energy and the lowest diffusivity, while the opposite is true for H2. And compared to C3H8, CO2 is more difficult to adsorb, but more diffuse. And the feed ratio has a significant effect on the overall reaction. When C3H8 is more than twice the amount of CO2, the adsorption efficiency of CO2 in the pores is very low. However, excess CO2 can also replace the adsorption of C3H8, reducing the efficiency of the reaction. The ratio of CO2 to C3H8 in the channel approaches 1:1 only when the feed ratio is around 1:3.