Potentialities of mass spectrometry on activation energy and secondary reactions determination of calcium oxalate thermal decomposition

This work investigates the potentialities of thermal analysis (TA) coupled with mass spectrometry (MS) technique by studying decomposition calcium oxalate monohydrate (CaC2O4·H2O). The aim this is twofold: to demonstrate, at first, efficacy coupling gravimetric (TG)-MS experimental approach check presence intermediate reactions beyond conventional three-step decomposition: dehydration, decarbonylation, and decarbonation; second, test reliability different modeling approaches in determining activation energy (E) including, as innovative alternative, use MS signals. TA carried out selected constant heating rates recording both analysis, differential analysis) profiles, and, simultaneously from data, signals total ion current currents monitor release H2O, CO, CO2 species. These results are effective E through based on maximum reaction rate method isoconversional procedures including TG Coupling TA-MS has allowed us concurrent dismutation carbon monoxide, occurring during decarbonylation event, determine corresponding value (E = 169.7 kJ/mol). present a surprising correlation between global enthalpy two involved second step their values. On whole, satisfy constraints usually adopted consistent majority datasets published literature subject.