Lattice-Engineered Cerium Dioxide Nanoparticles for Fuel Additives
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Solution Overview
Problem
Current methods for producing cerium dioxide nanoparticles are inefficient in creating small, uniform particles with transition metal dopants, requiring calcination and resulting in agglomeration and instability in non-polar environments.
Innovation Solution
A process involving an aqueous reaction mixture with cerous ion, transition metal ions, hydroxide ion, and a nanoparticle stabilizer, mechanically sheared and heated to form stable, monodisperse cerium dioxide nanoparticles with a cubic fluorite structure, which are then transferred to a non-polar medium using a surfactant.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If conventional methods are used to produce cerium dioxide nanoparticles, then particle size can be reduced, but particle uniformity and stability deteriorate due to agglomeration
Solution Approach 1:
The patent introduces a surfactant as an intermediary substance that adsorbs onto the nanoparticle surface, creating a steric barrier that prevents agglomeration. The surfactant molecules form a protective layer around the cerium dioxide particles, maintaining their dispersion stability in non-polar environments while preserving their small size and uniform distribution
Solution Approach 2:
The patent changes the chemical composition parameters by incorporating transition metal dopants (such as Cu, Zn, or Mn) into the cerium dioxide lattice at controlled concentrations. This doping modifies the crystal structure and surface properties, enhancing particle stability and preventing agglomeration while maintaining small particle size and uniformity
2Object-generated harmful factors
If transition metal dopants are added to enhance catalytic properties, then catalytic activity improves, but particle stability in non-polar environments deteriorates
Solution Approach 1:
The patent creates a composite material system by combining cerium dioxide with transition metal dopants (forming Ce1-xMxO2 solid solution) and coating with surfactant. This multi-component composite structure integrates the catalytic functionality of transition metals with the stabilizing effect of surfactant, achieving both enhanced catalytic activity and improved stability in non-polar environments simultaneously
3Ease of manufacture
If calcination is used to form cerium dioxide particles, then particle formation is achieved, but particle agglomeration occurs reducing nanoparticle quality
Solution Approach 1:
The patent performs preliminary stabilization by adding surfactant to the precursor solution before particle formation occurs. The surfactant adsorbs onto the forming particles during precipitation, creating a protective layer that prevents agglomeration during and after the calcination process, thus maintaining nanoparticle quality while still achieving complete particle formation
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Produces cerium dioxide nanoparticles with a mean diameter of 1-10 nm, maintaining stability and uniformity in both aqueous and non-polar environments, enhancing catalytic properties and fuel efficiency.
Implementation Method 1
providing temperature conditions effective to enable oxidation of cerous ion to ceric ion, thereby forming a product stream comprising transition metal-containing cerium dioxide nanoparticles
Implementation Method 2
transferred to a non-polar medium using a surfactant
Implementation Method 3
maintaining stability and uniformity in both aqueous and non-polar environments
Implementation Method 4
Aqueous Precipitation
Data Source
AI summary
A process for making cerium dioxide nanoparticles containing at least one transition metal (M) utilizes a suspension of cerium hydroxide nanoparticles prepared by mechanical shearing of an aqueous mixture containing an oxidant in an amount effective to enable oxidation of cerous ion to ceric ion, thereby forming a product stream that contains transition metal-containing cerium dioxide nanoparticles, Ce1-xMxO2, wherein “x” has a value from about 0.3 to about 0.8. The nanoparticles thus obtained have a cubic fluorite structure, a mean hydrodynamic diameter in the range of about 1 nm to about 10 nm, and a geometric diameter of less than about 4 nm. The transition metal-containing crystalline cerium dioxide nanoparticles can be used to prepare a dispersion of the particles in a nonpolar medium.