Thermal Analysis Kinetics of Pd-Doped SiO₂ Organic-Inorganic Hybrid Material

Abstract

Pd-doped SiO2 organic-inorganic hybrid material (Pd/M-SiO2) was prepared by sol-gel method and characterized by XRD, FTIR spectra and TG/DTG analysis. The most probable kinetic mechanism function, apparent activation energy and pre-exponential factor of the thermal decomposition for Pd/M-SiO2 material were calculated using the combined Coast-Redfern intergral and Αchar differential methods. Pd element in noncalcined Pd/M-SiO2 materials exists in PdCl2 form. FTIR spectroscopy confirmed the existence of hydrophobic Si−CH3 groups. The thermal decomposition process of Pd/M-SiO2 materials can be divided into four stages, with different mechanism functions. The activation energies are 76.37, 146.85, 208.90 and 413.89 kJ·mol−1 for the four stages, respectively, and the pre-exponential factors are 5.04×1012, 7.14×1013, 2.93×1012 and 6.56×1019 s−1, respectively. There is no obvious influence of the existence of metallic Pd0 on the thermal decomposition of methyl.