Thermochemistry of proton containing borosilicate, aluminosilicate and gallosilicate zeolite beta

The thermochemistry of proton containing borosilicate, aluminosilicate and gallosilicate zeolites with beta topology (B-BEA, Al-BEA and Ga-BEA) is described. Thermogravimetry and differential scanning calorimetry on these materials indicate the substitution of Al by Ga or B in the beta framework reduces the decomposition temperature. Water adsorption calorimetry directly measured the hydration enthalpies of these samples. B-BEA and Ga-BEA have less exothermic hydration enthalpies than Al-BEA. High temperature oxide melt solution calorimetry was performed to derive the formation enthalpies of hydrated samples (8.9–18.8 kJ/mol relative to oxides on TO2 molar basis). The formation enthalpies of dehydrated phases (33.2–55.1 kJ/mol relative to oxides on TO2 molar basis) were calculated from the formation enthalpies of hydrated phases and the hydration enthalpy.

Figure optionsDownload as PowerPoint slideResearch highlights
► Hydration enthalpy of zeolite beta was measured by water adsorption calorimetry.
► Formation enthalpy of zeolite beta was measured by solution calorimetry.
► The substitution of Al by B and Ga in zeolite beta affects the thermal stability.