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.