Cerium-Zirconium-Lanthanum-Yttrium Catalysts (24CeO₂-60Zr(Hf)O₂-3.5La₂O₃-12.5Y₂O₃) Specifications

Properties

Note: The above product information is based on theoretical data. For specific requirements and detailed inquiries, please contact us.

Product Description

Cerium-Zirconium-Lanthanum-Yttrium Catalyst (24CeO₂-60Zr(Hf)O₂-3.5La₂O₃-12.5Y₂O₃) is an advanced mixed oxide material engineered for demanding catalytic environments, particularly in automotive and industrial emission control systems. This formulation is optimized to deliver high redox activity, exceptional thermal stability, and prolonged performance even under extreme operating conditions.

Key Components and Their Roles

• Cerium Oxide (CeO₂): Serves as the central component, providing dynamic oxygen storage and release capabilities through reversible Ce⁴⁺/Ce³⁺ redox cycling. This mechanism is crucial for managing lean-to-rich transitions in three-way catalysts, ensuring optimal air-to-fuel ratios for effective pollutant conversion.

• Zirconium or Hafnium Oxide (Zr(Hf)O₂): Enhances the thermal stability of the catalyst, preventing sintering and preserving the active surface area during high-temperature exposure, which is essential for maintaining catalytic efficiency.

• Lanthanum Oxide (La₂O₃): Improves the textural properties of the catalyst by increasing surface area and promoting thermal durability. This leads to better dispersion of active sites and enhanced catalytic performance.

• Yttrium Oxide (Y₂O₃): Contributes to phase stabilization and enhances resistance to thermal shock. It helps maintain a stable crystal lattice structure throughout extended redox cycles, ensuring consistent catalyst performance.

Benefits

• High Oxygen Storage Capacity: Facilitates rapid oxygen release and uptake, essential for effective catalytic reactions.
• Superior Thermal Stability: Maintains structural integrity and catalytic activity even at elevated temperatures.
• Enhanced Redox Performance: Supports efficient oxidation-reduction cycling, crucial for various catalytic processes.
• Resistance to Sintering and Thermal Degradation: Ensures long-term durability and sustained catalytic efficiency.
• Optimal Surface Area: Provides ample active sites for catalytic reactions, enhancing overall performance.

Collectively, these properties result in a robust and efficient catalyst support material, ideal for applications requiring repeated oxidation-reduction cycling, such as automotive catalytic converters, fuel processing, and industrial gas treatment systems. The formulation ensures excellent dispersion of noble metals and retains its structural and chemical integrity under prolonged thermal stress.

Applications

1. Automotive Three-Way Catalytic Converters (TWCs): Acts as an oxygen storage component and support for noble metals (like Pt, Pd, Rh), facilitating the conversion of CO, NOₓ, and hydrocarbons into less harmful gases while maintaining optimal performance during lean-rich transitions.

2. Gasoline Particulate Filters (GPFs) and Diesel Oxidation Catalysts (DOCs): Enhances soot oxidation and improves emission control in gasoline and diesel exhaust treatment systems under varying operating temperatures.

3. Industrial Emission Control: Utilized in fixed-bed and monolithic catalyst systems for the abatement of VOCs (volatile organic compounds), CO, and other hazardous gases in power plants, refineries, and chemical manufacturing facilities.

4. Fuel Reforming Catalysts: Serves as a component or support in steam reforming or partial oxidation processes for hydrogen production, benefiting from high redox reactivity and sintering resistance.

5. Solid Oxide Fuel Cells (SOFCs): Employed as a buffer layer or support in SOFCs due to their ionic conductivity, phase stability, and compatibility with other cell components.

6. Oxygen and Gas Sensors: Used in sensing devices where quick and reversible oxygen exchange is critical for real-time detection and monitoring.

Packaging

Our products are packaged in customized cartons of various sizes based on the material dimensions. Small items are securely packed in PP (polypropylene) boxes, while larger items are placed in custom wooden crates. We ensure strict adherence to packaging customization and the use of appropriate cushioning materials to provide optimal protection during transportation.

Packaging Options:

• Carton
• Wooden Box
• Customized Packaging Solutions

Please review the packaging details provided for your reference. For special packaging needs, feel free to contact us.

Manufacturing Process

Testing Method

1. Chemical Composition Analysis: Verified using techniques such as Glow Discharge Mass Spectrometry (GDMS) or X-ray Fluorescence (XRF) to ensure compliance with purity requirements.

2. Mechanical Properties Testing: Includes tensile strength, yield strength, and elongation tests to assess material performance.

3. Dimensional Inspection: Measures thickness, width, and length to ensure adherence to specified tolerances.

4. Surface Quality Inspection: Checks for defects such as scratches, cracks, or inclusions through visual and ultrasonic examination.

5. Hardness Testing: Determines material hardness to confirm uniformity and mechanical reliability.

Please refer to the SMC testing procedures for detailed information.

FAQs

Q1. What is this catalyst used for?
A: It is primarily used in automotive catalytic converters, gasoline particulate filters, industrial emission control systems, and fuel reforming applications where high thermal stability and oxygen storage capacity are required.

Q2. What advantages does it offer over traditional ceria-zirconia materials?
A: The addition of lanthanum and yttrium oxides enhances thermal resistance, increases surface area, and stabilizes the catalyst structure during redox cycling, making it more durable and efficient under harsh conditions.

Q3. How does it help reduce emissions?
A: It facilitates rapid oxygen release and uptake during lean-rich transitions, improving the conversion of CO, NOₓ, and hydrocarbons into harmless gases in three-way catalytic converters.

Performance Comparison Table with Competitive Products

Ce-Zr-La-Y (24-60-3.5-12.5) vs. Competitive Catalysts

Additional Information

Common Preparation Methods

The Cerium-Zirconium-Lanthanum-Yttrium Catalyst (24CeO₂-60Zr(Hf)O₂-3.5La₂O₃-12.5Y₂O₃) is typically synthesized using a co-precipitation method. The process involves the following steps:

1. Preparation of Aqueous Solutions:
   Cerium nitrate, zirconium salt (e.g., zirconium chloride or nitrate), lanthanum nitrate, and yttrium nitrate are dissolved in water in stoichiometric proportions.

2. Reaction with a Base:
   A base such as ammonium hydroxide or sodium carbonate is added under controlled pH and stirring conditions to precipitate the metal hydroxides or carbonates.

3. Precipitation:
   The reaction mixture is allowed to precipitate, forming a homogeneous gel or precipitate of the mixed hydroxides/carbonates.

4. Aging:
   The precipitate is aged to enhance crystallinity and homogeneity, ensuring uniform distribution of all metal components.

5. Filtration and Washing:
   The aged precipitate is filtered and thoroughly washed to remove residual ions and impurities.

6. Drying:
   The washed precursor is dried at moderate temperatures to remove moisture content.

7. Calcination:
   The dried precursor is calcined at high temperatures (typically between 500°C and 800°C) to form a thermally stable, homogeneous mixed oxide with enhanced oxygen storage capacity, redox activity, and structural integrity.

This method yields a high-purity, nanostructured cerium-zirconium-lanthanum-yttrium oxide with significant surface area and porosity, making it suitable for various high-performance catalytic applications.

Characterization Techniques

To ensure the quality and performance of Cerium-Zirconium-Lanthanum-Yttrium Catalysts, the following characterization techniques are employed:

• X-ray Diffraction (XRD):
  Determines the crystalline structure and phase composition of the catalyst, ensuring the formation of a homogeneous mixed oxide phase.

• Scanning Electron Microscopy (SEM):
  Evaluates the morphology, particle size distribution, and surface characteristics of the catalyst particles.

• Transmission Electron Microscopy (TEM):
  Provides detailed insights into the internal structure and nanoscale features of the catalyst.

• Brunauer-Emmett-Teller (BET) Surface Area Analysis:
  Measures the specific surface area, which is critical for catalytic activity and oxygen storage capacity.

• Thermogravimetric Analysis (TGA):
  Assesses the thermal stability and weight changes during heating, indicating decomposition temperatures and stability under operating conditions.

• Inductively Coupled Plasma Mass Spectrometry (ICP-MS):
  Ensures precise determination of the elemental composition and purity of the catalyst.

• Fourier-Transform Infrared Spectroscopy (FTIR):
  Identifies functional groups and verifies the structural integrity of the mixed oxides.

• Temperature-Programmed Reduction (TPR):
  Evaluates the redox properties and oxygen mobility within the catalyst, essential for its performance in catalytic cycles.

• Surface Area and Pore Volume Analysis:
  Determines the porosity and surface characteristics, which are vital for catalytic activity and durability.

These comprehensive characterization methods ensure that the Cerium-Zirconium-Lanthanum-Yttrium Catalysts meet the highest standards required for their diverse applications in automotive emission control, industrial catalysis, and energy systems.