Multi-Sandwich Composite Catalyst for Tandem Reaction Control
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Solution Overview
Problem
Current catalysts for tandem reactions face challenges in achieving precise control over the distance between active sites, which affects catalytic performance due to issues with electron density and charge transfer, leading to suboptimal activity and selectivity.
Innovation Solution
A multi-sandwich composite catalyst is prepared by sequentially depositing a first oxide layer, a first active metal, an oxide interlayer, a second active metal, and a surface oxide layer on a template, followed by calcination and reduction, allowing for precise control of the distance between active sites through adjustable deposition cycles and layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the distance between active sites is too small, then the catalytic activity is improved, but the selectivity deteriorates due to excessive charge transfer and by-product formation
Solution Approach 1:
The patent introduces an oxide interlayer as a mediator between the two active metal sites. This interlayer acts as a buffer that controls the interaction between active sites, allowing electron density modulation without direct contact between metals, thus maintaining activity while preventing excessive charge transfer that leads to poor selectivity
Solution Approach 2:
The patent creates non-uniform local environments by depositing different oxide layers with specific thicknesses between active sites. The oxide interlayer provides localized electronic modification, creating distinct electronic environments at different positions while maintaining overall catalyst structure, enabling precise control over charge transfer at specific locations
2Manufacturing precision
If the distance between active sites is too far, then the selectivity is improved, but the catalytic activity deteriorates due to insufficient charge transfer
Solution Approach 1:
The oxide interlayer serves as an electronic mediator that facilitates charge transfer over longer distances. It provides a conductive pathway that maintains electron density and charge transfer efficiency even when physical distance between active sites increases, thus preserving catalytic activity while allowing improved selectivity
Solution Approach 2:
The patent modifies the electronic parameters of the catalyst system by introducing oxide layers with different thicknesses and compositions. This changes the electronic coupling between active sites, allowing tuning of charge transfer efficiency and electron density without changing the physical distance between metal particles
3Device complexity
If the distance between active sites is not precisely controlled, then the device complexity is reduced, but the catalytic performance deteriorates due to uncontrolled electron density and charge transfer
Solution Approach 1:
The patent segments the catalyst structure into distinct layers (oxide support layer, active metal layers, and oxide interlayer) with controllable thicknesses. This segmentation allows independent optimization of each layer's properties and thickness, enabling precise control over inter-site distance and electronic interactions through a systematic multi-layer architecture
Solution Approach 2:
The patent transitions from controlling distance in one dimension (physical separation) to controlling it through multiple dimensions including oxide layer thickness, oxide composition, and deposition cycles. This multi-dimensional approach provides finer control over electronic properties while maintaining a relatively simple physical structure
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 enhances catalytic performance by achieving better conversion rates and selectivity in tandem reactions, as demonstrated by the improved activity and selectivity of the multi-sandwich composite catalyst compared to catalysts without an oxide interlayer.
Implementation Method 1
sequentially depositing a first oxide layer, a first active metal, an oxide interlayer, a second active metal and a surface oxide layer on a template
Implementation Method 2
sequentially depositing a first oxide layer, a first active metal, an oxide interlayer, a second active metal and a surface oxide layer on a template
Implementation Method 3
sequentially performing calcination and reduction
Implementation Method 4
sequentially performing calcination and reduction
Data Source
AI summary
The present disclosure relates to a multi-sandwich composite catalyst and a preparation method and application thereof. The present disclosure provides a preparation method of a multi-sandwich composite catalyst, comprises the following steps: sequentially depositing a first layer oxide, a first active metal, an oxide interlayer, a second active metal and a surface oxide on a template, and sequentially performing calcination and reduction, thereby obtaining a multi-sandwich composite catalyst; wherein the first active metal and the second active metal are different kinds of active metals. In the present disclosure, a multi-sandwich structure is formed by depositing the oxides and active metals alternately, so that the position and spacing distance of the active centers can be precisely controlled. The multi-sandwich composite catalyst prepared by the method provided described herein has a higher conversion than that of a catalyst without an interlayer when used for the catalytic reaction.