Nitrous Oxide Decomposition Catalyst with Alkali Promoter
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Solution Overview
Problem
Existing catalysts for nitrous oxide decomposition, such as zeolite-supported iron and base metal oxides, face limitations in operating window, stability, and mechanical properties, making them unsuitable for a wide range of temperatures and applications.
Innovation Solution
A catalyst comprising oxides of cobalt, zinc, and aluminum with an alkali metal promoter, prepared through an aqueous solution precipitation, drying, and calcination process, offering improved activity and stability across a broad temperature range and enhanced mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If zeolite-supported iron catalysts are used, then catalytic activity is achieved, but operating window is limited due to water inhibition below 400°C and hydrothermal stability degradation above 600°C
Solution Approach 1:
The patent changes the chemical composition parameters by replacing zeolite-supported iron with base metal oxides (Co3O4, NiO, MnO2, ZnO, Al2O3) that have different thermal and hydrothermal stability characteristics, enabling operation across a wider temperature range without the same stability limitations
Solution Approach 2:
The patent creates a composite catalyst system by combining multiple base metal oxides (Co3O4, NiO, MnO2, ZnO, Al2O3) in specific ratios, where each component contributes different catalytic properties and stability characteristics, achieving both high activity and wide operating window
2Reliability
If base metal oxides are used, then operating window is improved, but bulk density increases leading to high mass of catalyst required per unit reactor volume
Solution Approach 1:
The patent optimizes the compositional parameters by controlling the ratios of base metal oxides (Co3O4: 30-70 wt%, NiO: 10-40 wt%, MnO2: 10-40 wt%, ZnO: 5-30 wt%, Al2O3: 5-30 wt%) to achieve the desired balance between activity, stability, and bulk density
Solution Approach 2:
The patent applies local quality by incorporating specific metal oxides in particular concentrations at different positions within the catalyst structure, where Co3O4 provides high activity, NiO and MnO2 enhance stability, and ZnO/Al2O3 control bulk density and mechanical properties
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 demonstrates high activity and stability for nitrous oxide decomposition at both low and high temperatures, withstanding increased water and ammonia concentrations, and exhibits lower bulk density and higher strength compared to previous catalysts, making it suitable for various applications.
Implementation Method 1
a catalyst for the decomposition of nitrous oxide... comprising oxides of cobalt, zinc and aluminium and an alkali metal promoter... for the decomposition of nitrous oxide in a gas stream
Implementation Method 2
precipitating the bulk metal oxide using an aqueous alkaline solution
Implementation Method 3
calcining the thus-formed catalyst particles
Data Source
AI summary
The present invention provides a catalyst for the decomposition of nitrous oxide, said catalyst comprising oxides of cobalt, zinc and aluminum and an alkali metal promoter.