In-situ IR study of thermal decomposition of dimethyl carbonate over Zn/Al mixed oxide catalysts

ZnO, ZnAl₂O₄ and Zn/Al mixed oxide catalysts were prepared by thermal decomposition of hydrotalcite-like layered precursors derived from urea precipitation at 1 073 K. Both ZnAl₂O₄ and ZnO phases were observed in ZAO-3 catalyst at 1 073 K from XRD patterns. The NH₃-TPD and CO₂-TPD results revealed that the acidity and basicity of Zn/Al mixed oxide catalysts changed with the introduction of Al. Combined with the in-situ FT-IR results of dimethyl carbonate (DMC) decomposition over ZAO-3(1 073 K), ZnAl₂O₄, ZnO at various temperatures, it was found that the synergistic effect between acidic and basic sites over ZAO-3(1 073 K) could stabilize DMC molecules and inhibit the decomposition of DMC.