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 Al2O3@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 Al2O3 supports and the strong interaction between the catalytically active Pd-CoAlO nanosheets and the Al2O3 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.