Designed synthesis of semi-embedded Pd over CeO2-ZrO2/Al2O3 as advanced three-way catalyst

Progress on metal-support interactions in Pd-based catalysts for automobile emission control

The interactions between metals and oxide supports, so-called metal-support interactions (MSI), are of great importance in heterogeneous catalysis. Pd-based automotive exhaust control catalysts, especially Pd-based three-way catalysts (TWCs), have received considerable research attention owing to its prominent oxidation activity of HCs/CO, as well as excellent thermal stability. For Pd-based TWCs, the dispersion, chemical state and thermal stability of Pd species, which are crucial to the catalytic performance, are closely associated with interactions between metal nanoparticles and their supporting matrix. Progress on the research about MSI and utilization of MSI in advanced Pd-based three-way catalysts are reviewed here. Along with the development of advanced synthesis approaches and engine control technology, the study on MSI would play a notable role in further development of catalysts for automobile exhaust control.

Morphology Effects on Structure-Activity Relationship of Pd/Y-ZrO2 Catalysts for Methane Oxidation

Pd/Y-ZrO2 catalysts were prepared by Y-ZrO2 with different morphologies (flower-like, spherical, reticulated, and bulk-specific morphology), which were prepared by hydrothermal synthesis. Activity evaluation and characterization results show that the morphology influences the microstructures of Y-ZrO2 and the chemical states of active Pd species, thus affecting the activity of methane oxidation. Bulk Pd/Y-ZrO2 exhibits the best CH4 oxidation activity and thermal stability due to the block shape exposed (101) surface, and the single tetragonal phase structure maintained after high-temperature aging. The relatively large-sized Pd particles and Pd0 jointly promote the catalytic oxidation of CH4.

Size effects of Pd nanoparticles supported over CeZrPAl for methane oxidation

Pd nanoparticles accompanied with distorted morphology result in considerable active sites and enhance the intrinsic activity for catalytic methane oxidation.