The effect of Pd precursor on Pd/Ce0.67Zr0.33O2 catalysts for automotive emission control

Three-way catalytic performance of a Pd/Ce0.67Zr0.33O2–Al2O3 catalyst for automotive emission control: the role of pretreatment gas

“…As is known to all, there are many factors inuencing the nature of the PdO x species in the catalysts, such as the Pd precursors, pretreatment gas, etc. In our previous study, 11 we discovered that a Pd/Ce 0.67 Zr 0.33 O 2 catalyst prepared with Pd(NO 3 ) 2 or Pd(NH 3 ) 4 (NO 3 ) 2 as a precursor had a higher dispersion of PdO x , which promoted CO oxidation, while the catalyst prepared using H 2 PdCl 4 as a precursor exhibited higher catalytic activity for NO conversion, due to a larger particle size. Liu et al 12 studied the effects of the pretreatment atmosphere on the catalytic performance of a Pd/Al 2 O 3 catalyst for benzene degradation and reasoned that the oxidation state of the Pd species decreased with H 2 pretreatment, leading to an increase in the catalytic activity, while the oxidation state increased with air pretreatment, accompanied by a decrease in the degradation of benzene.…”

Preparation of Al2O3–CeO2 by Hydrothermal Method Supporting Copper Oxide for the Catalytic Oxidation of CO and C3H8

“…The transition metal oxide catalysts have excellent catalytic oxidation activity for CO, especially copper-based oxides, is a promising low-cost substitute for precious metal catalysts. − Many previous studies have demonstrated that CuO/γ-Al 2 O 3 catalyst is an important heterogeneous catalyst that is widely used in many fields, such as CO oxidation, NO reduction, and methane combustion. − Single metal oxide carriers have disadvantages such as low catalytic oxidation performance, poor thermal stability, and negative sulfur resistance. Therefore, they need to be modified by adding another metal to make their properties complementary to prepare composite metal oxides and improve their catalytic properties. − CeO 2 has excellent oxygen storage and oxygen release properties, which mainly manifests as Ce 4+ /Ce 3+ interconversion in redox reactions . The introduction of CeO 2 can improve the dispersion of active ingredients of the samples, thereby improving the oxidation–reduction performance of the samples.…”