Novel nanocrystalline Ga–Al–Zn complex oxide: catalyst for simultaneous treatment of NPAC and lean NOx

Nanocrystalline Ga–Al–Zn complex-oxide (designated here as nano-GAZ) has been successfully synthesized using hydrothermal method. Using TEM, BET, FTIR, DTA–TGA, and XRD, synthesized nano-GAZ particles are shown as high-surface-area nanoparticles comprising typical spinel crystal structures. The nano-GAZ catalyst was tested as a new deNPAC catalyst, using pyridine as the model NPAC compound. The reaction results show that pyridine could be completely oxidized over nano-GAZ catalyst above 400 °C. Furthermore, NO formation was significantly decreased due to the excellent performance of the nano-GAZ catalyst for the selective catalytic reduction of NOx with hydrocarbon in the presence of excess oxygen. An optimal reaction temperature at around 440–500 °C was observed to achieve complete catalytic oxidation of pyridine with the lowest NOx formation. These results demonstrate a promising approach for dual-mitigation of NPAC and NOx pollutants using nano-GAZ catalyst.