Deactivation Resistant Photocatalyst Pore Structure
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Solution Overview
Problem
Photocatalysts in air purification systems are prone to deactivation due to mineralization of silicon compounds like siloxanes, leading to reduced efficiency and increased maintenance costs.
Innovation Solution
A porous photocatalyst with a specific pore structure, comprising cylindrical pores with a majority of the surface area in pores 5 nm or larger, which reduces deactivation by minimizing blockage from deposits and maintaining activity over time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional photocatalysts are used, then initial photocatalytic activity is achieved, but deactivation occurs due to mineralization of silicon compounds leading to reduced efficiency and shorter service life
Solution Approach 1:
The patent applies porous materials by designing a photocatalyst with a specific pore structure comprising cylindrical pores with a mode diameter of 10 nm or greater. This porous structure prevents blockage from mineralized silicon compounds while maintaining high surface area for photocatalytic activity, thereby resolving the contradiction between initial activity and long-term stability
Solution Approach 2:
The patent changes the physical parameter of pore size distribution, specifically requiring that the mode of the pore size distribution be 10 nm or greater. This parameter change optimizes the balance between surface area availability for catalysis and resistance to pore blockage from deposits, achieving both high initial activity and extended service life
2Productivity
If photocatalyst surface area is increased to improve activity, then more active sites are available, but blockage from deposits occurs more readily reducing effectiveness
Solution Approach 1:
The patent utilizes porous materials with a specific pore size distribution (mode ≥10 nm) that provides high surface area for photocatalytic activity while the larger pore dimensions prevent blockage from mineralized deposits. This resolves the contradiction by allowing both high productivity through increased surface area and high reliability through resistance to deactivation
Solution Approach 2:
The patent transitions from considering only total surface area to incorporating pore size distribution as an additional dimensional parameter. By specifying that the mode of pore size distribution should be 10 nm or greater, the invention adds this dimensional constraint that simultaneously enables high surface area for activity while preventing deposit blockage, thus resolving the contradiction between productivity and reliability
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 porous photocatalyst structure significantly increases the longevity of the air purification system by resisting deactivation, with a projected life expectancy of at least 6 times longer than conventional systems when challenged by hexamethyldisiloxane, maintaining 20% of initial activity after 10,000 hours compared to 1,700 hours for conventional systems.
Implementation Method 1
comprising cylindrical pores with a majority of the surface area in pores 5 nm or larger
Implementation Method 2
Photocatalytic Oxidation (PCO) is a technology used for elimination or reduction of the level of contaminants in a fluid, like air or water, using the chemical action of light
Implementation Method 3
When ultraviolet (UV) light is used to energize the photocatalyst, the technology is more specifically termed Ultraviolet Photocatalytic Oxidation (UV-PCO)
Data Source
AI summary
The present disclosure relates to a fluid purification device that has a deactivation resistant photocatalyst having nanocrystallites of less than 14 nanometers (nm) in diameter with at least 200 m2 surface area/cm3 of skeletal volume in cylindrical pores of 5 nm in diameter or larger, with the mode of the pore size distribution 10 nm or more.