The lanthanide doping effect on toluene catalytic oxidation over Pt/CeO₂ catalyst.

Area of Science:

• Heterogeneous Catalysis
• Materials Science
• Environmental Chemistry

Background:

• Platinum supported on ceria (Pt/CeO2) catalysts are widely studied for oxidation reactions.
• Lanthanide doping of ceria can modify its physicochemical properties and catalytic performance.
• Understanding doping effects is crucial for optimizing catalyst design for environmental applications like toluene oxidation.

Purpose of the Study:

• To investigate the effect of lanthanide doping on the properties of Pt/CeO2 catalysts.
• To evaluate the catalytic activity of these doped catalysts for toluene oxidation.
• To elucidate the relationship between dopant properties (ion radius, valence state) and catalytic performance.

Main Methods:

• Synthesis of lanthanide-doped ceria supports (La, Pr, Nd, Sm, Gd) via hydrothermal method.
• Loading of platinum nanoparticles onto the synthesized ceria-based supports.
• Characterization of catalyst properties and evaluation of catalytic activity for toluene oxidation.

Main Results:

• Lanthanide doping significantly impacts the physicochemical properties and catalytic activity of Pt/CeO2.
• Gadolinium (Gd) doping, due to its smaller ion radius and low valence state, enhances oxygen vacancy formation.
• Increased oxygen vacancies promote electron transfer to Pt, creating electron-rich, under-coordinated Pt sites favorable for toluene oxidation, leading to enhanced activity, stability, and resistance to concentration impacts.

Conclusions:

• Lanthanide doping, particularly Gd, effectively enhances the catalytic performance of Pt/CeO2 for toluene oxidation.
• The catalytic activity is strongly dependent on the ion radius and valence state of the lanthanide dopant.
• The Pt/CeGdO2 catalyst demonstrates superior reaction stability and robustness against concentration variations.