The Si/Al ratio in H-Mordenite zeolites plays a crucial role in determining their acidity and catalytic performance. A higher Si/Al ratio typically results in a more hydrophobic and thermally stable zeolite, while a lower Si/Al ratio leads to a higher concentration of acidic sites and stronger acidity. To investigate the interaction between acid site density and Si/Al ratio in H-Mordenite zeolites using computational methods, we can follow these steps:1. Build a series of H-Mordenite zeolite models with varying Si/Al ratios: Start by constructing a series of H-Mordenite zeolite unit cell models with different Si/Al ratios e.g., 10, 20, 30, etc. . Replace some Si atoms with Al atoms in the zeolite framework to create the desired Si/Al ratios. Ensure that the overall charge neutrality is maintained by adding H+ ions protons to the oxygen atoms connected to the Al atoms.2. Geometry optimization: Perform geometry optimization of the H-Mordenite zeolite models using density functional theory DFT or other suitable computational methods. This step will provide the optimized atomic positions and lattice parameters for each Si/Al ratio.3. Calculate the acid site density: Determine the number of acidic sites protons in each H-Mordenite zeolite model and normalize it by the unit cell volume or mass to obtain the acid site density.4. Calculate the acidity strength: The acidity strength can be estimated by calculating the deprotonation energy of the acidic sites. This can be done by removing a proton from the zeolite model and calculating the energy difference between the protonated and deprotonated states. A lower deprotonation energy indicates a stronger acid site.5. Analyze the relationship between Si/Al ratio, acid site density, and acidity strength: Plot the acid site density and acidity strength as a function of the Si/Al ratio. Analyze the trends and correlations between these properties to understand how the Si/Al ratio affects the acidity of H-Mordenite zeolites.6. Validate the computational results with experimental data: Compare the computational results with experimental data on the acidity of H-Mordenite zeolites with varying Si/Al ratios. This will help validate the computational approach and provide insights into the accuracy of the predictions.By following these steps, we can gain a better understanding of the relationship between the Si/Al ratio, acid site density, and acidity strength in H-Mordenite zeolites. This information can be useful for designing zeolite catalysts with tailored acidity properties for specific chemical reactions and industrial applications.