Characterization and Activity of MnO/γ-Al₂O₃ for Hydrogenation of Methyl Benzoate to Benzaldehyde

The activities of a MnO/γ-Al₂O₃ catalyst for the selective reduction of methyl benzoate to benzaldehyde have been studied in a continuous flow reactor. Characterization of the catalyst has been conducted by XRD, XPS, NH₃-TPD and TPD-IR. XRD and XPS results revealed that the steady state catalyst is mainly MnO₂/γ-AlO₃ before reduction and MnO/γ-Al₂O₃ after reduction. Monolayer dispersion capacity obtained by XPS method is about w (Mn)11.3% TPD-IR results revealed that there are only L acidic centers on the catalytic surface. NH₃-TPD determinations have verified that the catalyst with a certain number of moderate strength acidic sites is advantageous to hydrogenation of methyl benzoate to benzaldehyde.