Zeolite Encapsulated Metal Nanoparticles Sinter-Stability
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Solution Overview
Problem
Current methods for producing sinter-stable zeolite or zeotype encapsulated metal nanoparticles are inefficient, expensive, and difficult to scale up for industrial applications, as they often require exotic materials and complex synthesis processes, and lack shape-selective catalytic properties.
Innovation Solution
A method involving the addition of metal precursors to a silica or alumina source, followed by reduction and carbon templating to form carbon-coated metal nanoparticles, which are then encapsulated within a zeolite or zeotype structure through hydrothermal treatment, allowing for the removal of the carbon template and isolation of sinter-resistant nanoparticles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional methods are used to produce zeolite encapsulated metal nanoparticles, then sinter-stability is achieved, but the production process is inefficient, expensive, and difficult to scale up
Solution Approach 1:
The metal nanoparticles are synthesized and positioned within the zeolite framework during the zeolite crystallization process itself, rather than attempting to introduce pre-formed nanoparticles afterward. This preliminary action ensures uniform distribution and strong anchoring of metal species throughout the zeolite structure, achieving sinter-stability while enabling scalable production through conventional hydrothermal synthesis methods
Solution Approach 2:
The invention employs a two-stage temperature process: initial crystallization at moderate temperatures (80-180°C) to form the zeolite framework with embedded metal nanoparticles, followed by high-temperature calcination (400-600°C) to remove organic templates and stabilize the structure. This parameter change strategy achieves both sinter-resistance and production efficiency
2Reliability
If exotic materials and complex synthesis processes are used, then sinter-stable encapsulated nanoparticles are produced, but synthesis costs increase
Solution Approach 1:
The invention uses inexpensive, readily available materials including common metal salts (nitrate, chloride, acetate), standard zeolite precursors (silica, alumina), and conventional organic structure-directing agents. These disposable reagents are consumed during synthesis but enable production of stable, reusable catalysts at low cost without requiring exotic or specialized materials
Solution Approach 2:
The synthesis method is universally applicable to multiple metal types (precious and base metals) and various zeolite structures (ZSM-5, beta, Y, mordenite) using the same general procedure. This multi-functionality reduces development costs and enables standardized production across different catalyst formulations
3Manufacturing precision
If post-synthesis treatments are used to introduce nanoparticles, then encapsulation is achieved, but control over size and location is difficult
Solution Approach 1:
Metal precursors are introduced into the zeolite framework during the crystallization stage, allowing the zeolite structure to form around and encapsulate the metal species in situ. This preliminary incorporation provides precise control over nanoparticle size and location throughout the zeolite crystal structure, eliminating the need for complex post-synthesis modification steps
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
This method enables the production of sinter-resistant, shape-selective zeolite encapsulated metal nanoparticles that are stable at elevated temperatures, accessible through the zeolite framework, and suitable for industrial-scale production, enhancing catalytic performance and reducing synthesis costs.
Implementation Method 1
Reducing the one or more metal precursors to form metal nanoparticles on the surface of the silica or alumina source
Implementation Method 2
Passing a gaseous hydrocarbon, alkyl alcohol or alkyl ether over the silica or alumina source with the supported metal nanoparticles to form a carbon template coated zeolite
Implementation Method 3
Adding a structure directing agent to the carbon template coated zeolite, zeolite-like or zeotype precursor composition so that the silica or alumina is dissolved in an aqueous alkaline media creating a supersaturated solution
Implementation Method 4
Crystallising the zeolite, zeolite-like or zeotype gel composition by subjecting said composition to a hydrothermal treatment
Implementation Method 5
The carbon template is removed by combustion. This will lead to uniformed micropores or mesopores in the zeolite
Data Source
Figure 1(a)~1(b)
Figure 2a
Figure 2b
AI summary
The invention therefore relates to a method for producing zeolite, zeolite-like or zeotype encapsulated metal nanoparticles, the method comprises the steps of: 1) Adding one or more metal precursors to a silica or alumina source; 2) Reducing the one or more metal precursors to form metal nanoparticles on the surface of the silica or alumina source; 3) Passing a gaseous hydrocarbon, alkyl alcohol or alkyl ether over the silica or alumina supported metal nanoparticles to form a carbon template coated zeolite, zeolite-like or zeotype precursor composition; 4a) Adding a structure directing agent to the carbon template coated zeolite, zeolite-like or zeotype precursor composition thereby creating a zeolite, zeolite-like or zeotype gel composition; 4b) Crystallising the zeolite, zeolite-like or zeotype gel composition by subjecting said composition to a hydrothermal treatment; 5) Removing the carbon template and structure directing agent and isolating the resulting zeolite, zeolite-like or zeotype encapsulated metal nanoparticles.