Hierarchical Core–Shell Al₂O₃@Pd-CoAlO Microspheres for Low-Temperature Toluene Combustion

The high-efficiency catalyst is the key factor of volatile organic compounds (VOCs) catalytic combustion. Herein, hierarchical core–shell Al 2 O 3 @Pd-CoAlO (Pd-CoAlO-Al) microspheres have been successfully prepared and used for toluene combustion. The experimental results reveal that the core–shell Pd-CoAlO-Al exhibits outstanding catalytic efficiency due to the homogeneous distribution of Pd-CoAlO nanosheets on Al 2 O 3 supports and the strong interaction between the catalytically active Pd-CoAlO nanosheets and the Al 2 O 3 supports. In particular, the catalytically active PdO contributes to the excellent catalytic efficiency. In addition, the in situ DRIFTS results indicate that the benzoate species are the main intermediate species in toluene combustion.