Does the cal-ad method distinguish differences in the acid sites of H-MFI?

An experiment was conducted to examine the effectivity of the cal-ad method using vapor-phase measurements for the coadsorption of pyridine and n-hexane in the zeolite H-MFI. The cal-ad method involved calorimetric measurements of solid acidity in the presence of a solvent. The findings revealed that equilibrium is not achieved for pyridine titration measurements in a solvent at room temperature. This indicates that the ability of the cal-ad method to distinguish Bronsted-acid sites of widely different strengths in H-MFI is unproven.