Oxidative Destruction of Hydrocarbons on a New Zeolite-like Crystal of Ca₁₂Al₁₀Si₄O₃₅ Including O₂^- and O₂²^- Radicals

Abstract

To develop a nonmetal catalyst to decompose hydrocarbons, a new zeolite-like Ca12Al10Si4O35 was prepared by calcining hydrogarnet, Ca3Al2(SiO4)0.8(OH)8.8, a hydrothermal reaction product from a mixture of CaO, Al2O3 sol, and amorphous SiO2. The X-ray diffraction analysis showed the framework of (Al,Si)O4 tetrahedra formed in the Ca12Al10Si4O35 crystal. ESR measurement and Raman spectroscopy revealed that both superoxide anions (O2-) and peroxide species (O22-) existed in the cavity of the framework. Due to the O2- and O22- species present, Ca12Al10Si4O35 exhibited high activity for the oxidation of hydrocarbons to carbon oxides (CO2 and CO) and H2O at >400 °C.