Carbon-Supported Platinum Nanoparticles via Urea Complex Adsorption
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Solution Overview
Problem
Existing methods for synthesizing carbon-supported platinum group metal nanoparticles, such as impregnation-reduction and polyol methods, have limitations in terms of morphology, nanoparticle size distribution, and catalytic properties, and do not effectively utilize noble metals due to high costs and complexity.
Innovation Solution
A novel method using urea or urea derivatives as complexing agents to adsorb and reduce platinum group metals on carbon supports, allowing for the formation of nanoparticles with improved morphology and catalytic properties by binding metals via nitrogen atoms and carbon supports via oxygen atoms, enabling better coverage and utilization of noble metals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional impregnation-reduction or polyol methods are used for synthesis, then catalysts can be produced, but the noble metal utilization is poor due to high costs and complexity
Solution Approach 1:
Urea serves as an intermediary complexing agent that mediates between the metal precursor and carbon support. It forms stable metal-urea complexes that facilitate controlled adsorption onto carbon support and subsequent reduction, simplifying the synthesis process while improving metal utilization and catalytic performance
Solution Approach 2:
The invention changes the chemical parameters by using urea complexing agents to form metal-urea complexes with specific stability constants. This parameter change enables controlled release and deposition of metals on carbon support, achieving better nanoparticle dispersion and catalytic activity without complex procedures
2Area of stationary object
If conventional methods are used, then synthesis can be performed, but the active surface area and metal utilization are limited
Solution Approach 1:
The metal is pre-complexed with urea before adsorption onto carbon support. This preliminary complexation action ensures controlled deposition and uniform distribution of metal nanoparticles on the carbon surface, maximizing the active surface area and noble metal utilization efficiency
Solution Approach 2:
The carbon support with its porous structure provides high surface area for metal nanoparticle deposition. The urea complexing agent facilitates metal adsorption onto these porous surfaces, enabling efficient utilization of both the carbon support's surface area and the noble metal quantity
3Shape
If existing synthesis methods are applied, then catalysts are obtained, but morphology and nanoparticle size distribution are not optimized
Solution Approach 1:
By changing the chemical environment through urea complexation, the invention achieves controlled nucleation and growth of metal nanoparticles. The stability constant of metal-urea complexes and controlled reduction conditions enable precise control over nanoparticle size distribution and morphology, producing uniform spherical particles with optimized catalytic properties
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
The method achieves a high active surface area, efficient catalytic performance, and cost-effective synthesis of carbon-supported platinum group metal nanoparticles with uniform size distribution, enhancing the utilization of noble metals and modifying the carbon support's surface properties for improved catalytic activity.
Implementation Method 1
the urea complexing agent binds the platinum group metals via nitrogen atoms
Implementation Method 2
binds to the surface of carbon support via oxygen atoms. This provides a very good coverage of the platinum group metals on the carbon support
Implementation Method 3
reducing the metal from the complexes adsorbed on the carbon support as obtained in step (b) to metal nanoparticles
Data Source
AI summary
The presented invention relates to a method of synthesis of carbon-supported platinum group metal or metal alloy nanoparticles, which comprises the following steps:adsorbing on carbon support complexes of a platinum group metal with a urea complexing agent selected from a group comprising urea, urea derivative, a mixture of urea with at least one urea derivative, and a mixture of at least two urea derivatives; andreducing the complexes adsorbed on the carbon support to metal nanoparticles, forming a product of carbon-supported metal nanoparticles.The invention also provides the use of the carbon-supported platinum group metal or metal alloy nanoparticles obtained by the method of the invention as catalyst.The present invention further relates to a method of adsorption of precursors of platinum group metals on the surface of a carbon support and use of complexes of platinum group metals with urea complexing agent for adsorption of platinum group metal precursors on carbon support.