Supported Palladium Catalyst With Local Basic Sites for Stable Hydrogenation
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Solution Overview
Problem
Existing palladium-based catalysts face issues such as high cost, narrow active temperature ranges, and susceptibility to deactivation, particularly in the presence of oxygen, limiting their application in catalytic reactions.
Innovation Solution
A supported palladium catalyst with an overall weakly acidic surface environment and specific weakly basic sites, achieved through the introduction of modifying components like Bi, Sb, Pb, Sn, Zn, W, Mn, Si, Re, Group VIII elements, alkali metals, alkaline earth metals, Group IIIA elements, Group IB elements, rare earth elements, and halogen elements, and a specific alkalization treatment process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pure noble metal catalysts are used, then catalytic activity is high, but cost is high and the catalyst is susceptible to deactivation
Solution Approach 1:
The patent introduces modifying components (Bi, Sb, Pb, Sn, Zn, W, Mn, Si, Re, Group VIII elements, alkali metals, alkaline earth metals, Group IIIA elements, Group IB elements, rare earth elements, or halogen elements) that create local basic sites on the catalyst surface. This local modification approach maintains the overall acidic support environment while providing specific local regions with basic properties to enhance catalyst stability and reduce noble metal deactivation.
Solution Approach 2:
The patent creates a composite catalyst system combining acidic support (refractory metal oxides, silicon oxide, or activated carbon) with modifying components that provide basic sites. This composite structure leverages the synergistic effect between acidic and basic sites, where the acidic support provides overall catalytic activity while the basic modifying components enhance stability and reduce noble metal susceptibility to deactivation.
2Productivity
If acidic catalysts are used, then many reactions proceed smoothly, but coking occurs in hydrogenation reactions
Solution Approach 1:
The patent introduces modifying components (Bi, Sb, Pb, Sn, Zn, W, Mn, Si, Re, Group VIII elements, alkali metals, alkaline earth metals, Group IIIA elements, Group IB elements, rare earth elements, or halogen elements) that create local basic sites on the catalyst surface. This local modification approach maintains the overall acidic support environment while providing specific local regions with basic properties to suppress coking during hydrogenation reactions.
Solution Approach 2:
The patent modifies the surface chemical properties by introducing basic modifying components onto the acidic support, changing the local surface chemistry from purely acidic to having both acidic and basic characteristics. This parameter change in surface acidity/basicity balance enables the catalyst to maintain high reaction rates while suppressing coking formation during hydrogenation.
3Object-generated harmful factors
If alkaline catalysts are used, then coking is avoided in hydrogenation reactions, but deactivation occurs at higher alkalinity
Solution Approach 1:
The patent introduces modifying components (Bi, Sb, Pb, Sn, Zn, W, Mn, Si, Re, Group VIII elements, alkali metals, alkaline earth metals, Group IIIA elements, Group IB elements, rare earth elements, or halogen elements) that create local basic sites on the catalyst surface. This local modification approach provides basic sites to suppress coking while maintaining the overall acidic support environment, avoiding the deactivation issues associated with highly alkaline catalysts.
Solution Approach 2:
The patent creates a composite catalyst system combining acidic support with basic modifying components. This composite structure provides a balanced surface environment with both acidic and basic sites, where the acidic support maintains catalyst stability and the basic modifying components suppress coking, avoiding the deactivation problems of purely alkaline catalysts.
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 catalyst exhibits improved catalytic performance in hydrogenation reactions, particularly in the selective hydrogenation of alkyne and polyunsaturated hydrocarbons, with enhanced activity and selectivity, while inhibiting unwanted side reactions like polymerization.
Implementation Method 1
The surface acidity or alkalinity of the support directly affects the degree of 'metal-support interaction' on the catalyst surface and the dispersion state of the active metal
Implementation Method 2
Palladium (Pd)-based catalysts have been widely used in the petrochemical industry; for example, catalytic reforming, isomerization and dehydrogenation of alkanes and aromatics, selective hydrogenation in olefin production
Data Source
Figure 1A~1B
Figure 1C~1D
Figure 1E~1F
AI summary
Disclosed are a supported palladium catalyst, and preparation and use thereof, the catalyst comprising a support, and palladium and a modified component supported on the support, wherein the support is selected from refractory metal oxides, silicon oxide, activated carbon, or combinations thereof, and the modified component is selected from Bi, Sb, Pb, Sn, Zn, W, Mn, Si, Re, Group VIII elements other than palladium, alkali metal elements, alkaline earth metal elements, Group IIIA elements, Group IB elements, rare earth elements, halogen elements, or combinations thereof, wherein according to an analysis on in-situ infrared spectroscopy of pyrrole adsorption carried out at 40°C, the catalyst exhibits absorption peak(s) in the range of 3251-3410 cm-1. The supported palladium catalyst features an overall weakly acidic surface environment with specific weakly basic sites, resulting in better catalytic performance of the catalyst.