Low Surface Area Catalyst Coated with Ionic Liquid
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current catalysts for selective hydrogenation of acetylenic hydrocarbons face challenges in achieving high selectivity and activity while maintaining thermal stability, particularly due to the high surface area requirements and costs associated with using support materials with high specific surface areas.
Innovation Solution
A catalyst composition with a BET surface area of ≤ 9 m²/g coated with a small amount of ionic liquid, utilizing pre-formulated supported palladium shell catalysts with promoters like silver, gold, or zinc, and applying a thin layer of ionic liquid to enhance selectivity and activity without significant loss of catalyst activity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If support materials with high specific surface area are used to maintain catalyst activity, then catalyst activity is improved, but costs increase significantly
Solution Approach 1:
The patent applies parameter changes by reducing the BET surface area of the support material from conventional high values (e.g., 100-300 m²/g) to low values (≤9 m²/g), while compensating for the activity loss through ionic liquid coating. This parameter change fundamentally alters the catalyst design approach, allowing cost reduction without sacrificing performance.
Solution Approach 2:
The patent creates a composite catalyst system combining support material with ionic liquid coating. The ionic liquid layer (containing compounds like imidazolium, pyridinium, or pyrrolidinium cations with appropriate anions) forms a composite structure that enhances the catalytic properties of the palladium-containing catalyst, compensating for the reduced surface area and maintaining high activity at lower costs.
2Manufacturing precision
If ionic liquid is applied to enhance selectivity and activity, then selectivity is improved, but catalyst activity may be lost
Solution Approach 1:
The patent optimizes the ionic liquid content parameter, specifying it should be 0.1-10 wt% of the total catalyst weight. This precise parameter control ensures that enough ionic liquid is present to enhance selectivity through improved acetylene adsorption and reaction pathways, while preventing excessive coating that would block active sites and reduce catalyst activity.
Solution Approach 2:
The ionic liquid is applied as a surface coating on the support material, creating a localized functional layer. This local quality enhancement concentrates the selectivity-improving effects at the catalyst surface where reactants interact, while the bulk support material maintains its structural integrity and porosity for reactant diffusion, thus preserving overall catalyst activity.
3Quantity of substance
If low BET surface area catalysts are used to reduce costs, then costs are reduced, but selectivity and activity may deteriorate
Solution Approach 1:
The patent creates a composite structure where the ionic liquid coating on the low surface area support material provides the necessary selectivity enhancement. The ionic liquid compounds (with specific cations like imidazolium, pyridinium, or pyrrolidinium and appropriate anions) create favorable local environments for selective acetylene hydrogenation, compensating for the reduced surface area and maintaining high selectivity despite lower costs.
Solution Approach 2:
The patent fundamentally changes the selectivity enhancement mechanism from relying on high surface area to relying on ionic liquid coating. By specifying the ionic liquid content (0.1-10 wt%) and composition, the patent creates a new parameter regime where selectivity is controlled by the chemical properties of the ionic liquid rather than the physical surface area of the support.
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 composition achieves high selectivity in hydrogenating acetylene to ethylene with a higher 'run-away' temperature and reduced catalyst activity loss, using minimal ionic liquid quantities, thereby improving operational efficiency and reducing costs.
Implementation Method 1
A catalyst composition for selective hydrogenation with improved characteristics, in particular for the selective hydrogenation of acetylenic hydrocarbons
Implementation Method 2
utilizing pre-formulated supported palladium shell catalysts with promoters like silver, gold, or zinc, and applying a thin layer of ionic liquid to enhance selectivity and activity
Implementation Method 3
the acetylene is selectively hydrogenated into ethylene
Data Source
AI summary
This invention relates to heterogeneous catalysts useful for selective hydrogenation of unsaturated hydrocarbons, comprising palladium and optionally a promoter, supported on a substrate, having an uncoated BET surface area of ≤ 9 m2/g, the surface being coated with an ionic liquid. Also described are methods of making the catalysts and methods of selective hydrogenation of acetylene and/or dienes in front-end mixed olefin feed streams.