Moisture-resistant catalyst for air pollution remediation and method of making the same
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional zeolite-based and activated carbon-based adsorbents have low efficiency and require frequent maintenance for ammonia removal, and catalytic oxidation processes face challenges with low catalytic activity under near-ambient conditions and poor selectivity for complete mineralization of nitrogen-containing pollutants.
Innovation Solution
A moisture-resistant catalyst system comprising a metal oxide catalyst supported on an inorganic oxide with a hydrophobic porous framework, allowing operation at various humidity levels and enhancing catalytic activity for ammonia and organoamines oxidation into nitrogen and carbon dioxide.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional zeolite-based and activated carbon-based adsorbents are used for ammonia removal, then ammonia can be adsorbed from air, but the adsorption efficiency is low and frequent maintenance is required due to saturation and degradation
Solution Approach 1:
The patent changes the chemical state of the catalyst by using reduced metal oxides (such as Cu0/Cu+, Fe0/Fe2+, Co0/Co2+) instead of conventional adsorbents. This parameter change in oxidation state enables catalytic oxidation activity that converts ammonia to nitrogen, dramatically improving removal efficiency and eliminating saturation issues that require frequent maintenance
Solution Approach 2:
The patent creates a composite catalyst system comprising reduced metal oxide nanoparticles supported on metal oxides (such as Cu0/Cu+-TiO2, Fe0/Fe2+-ZrO2, Co0/Co2+-Al2O3). This composite structure combines the high catalytic activity of reduced metal oxides with the stability and support properties of metal oxide substrates, achieving both high efficiency and long operational life
2Temperature
If catalytic oxidation process is used for ammonia removal, then operating temperature can be decreased, but catalytic activity under near-ambient conditions remains low and selectivity for complete mineralization is poor
Solution Approach 1:
The patent changes the electronic and geometric parameters of the catalyst by reducing metal oxides to lower oxidation states (Cu0/Cu+, Fe0/Fe2+, Co0/Co2+). This parameter change creates more active sites and enhances electron transfer capability, enabling high catalytic activity at near-ambient temperatures while maintaining complete mineralization selectivity
Solution Approach 2:
The patent creates local active sites with specific electronic structures on the reduced metal oxide surfaces. These localized regions with unique electronic properties (such as Cu0/Cu+ interfaces, Fe0/Fe2+ boundaries) provide high catalytic activity and selectivity for ammonia oxidation at low temperatures, while the bulk material provides structural stability
3Productivity
If conventional catalysts are used for catalytic oxidation, then ammonia can be oxidized, but nitrogen oxide products are formed instead of complete mineralization to nitrogen
Solution Approach 1:
The patent changes the oxidation state parameter of the metal catalyst from +2 or +3 to 0 or +1 (Cu0/Cu+, Fe0/Fe2+, Co0/Co2+). This parameter change modifies the catalyst's oxygen species and reaction pathways, enabling complete mineralization of ammonia to nitrogen gas while suppressing the formation of nitrogen oxide byproducts, achieving both high conversion and high selectivity
4Adaptability or versatility
If catalyst is used in humid conditions, then ammonia removal can continue, but catalytic activity decreases due to moisture sensitivity
Solution Approach 1:
The patent designs composite catalysts where reduced metal oxides are supported on stable metal oxide substrates (TiO2, ZrO2, Al2O3). This composite structure provides moisture resistance from the stable support while maintaining catalytic activity from the reduced metal oxide active sites, enabling operation across a wide humidity range without activity loss
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 system achieves higher reaction rates and nitrogen selectivity across a wide range of humidity levels, maintaining activity and selectivity, thus overcoming the limitations of conventional adsorbents and oxidation processes.
Implementation Method 1
catalytic oxidation process, which can significantly decrease the operating temperature of the thermal oxidation process
Implementation Method 2
catalyze the oxidation of ammonia in air into nitrogen and water
Implementation Method 3
a porous framework for immobilizing the at least one metal oxide catalyst and the at least one inorganic oxide support, where the porous framework is moisture-resistant
Data Source
AI summary
The moisture-resistant catalyst for air pollution remediation is a catalyst with moisture-resistant properties, and which is used for removing nitrogen compound pollutants, such as ammonia (NH3), from air. The moisture-resistant catalyst for air pollution remediation includes at least one metal oxide catalyst, at least one inorganic oxide support for supporting the at least one metal oxide catalyst, and a porous framework for immobilizing the at least one metal oxide catalyst and the at least one inorganic oxide support, where the porous framework is moisture-resistant. As non-limiting examples, the at least one metal oxide catalyst may be supported on the at least one inorganic oxide support by precipitation, impregnation, dry milling, ion-exchange or combinations thereof. The at least one metal oxide catalyst supported on the at least one inorganic oxide support may be physically embedded in the porous framework.