Reduced Iron Oxide RWGS Catalyst for High CO Selectivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional catalysts for the reverse water gas shift (RWGS) reaction face challenges in achieving high selectivity and conversion of carbon dioxide to carbon monoxide at moderate temperatures while minimizing the formation of side products and preventing rapid catalyst degradation due to high temperatures and thermal cycling.
Innovation Solution
The use of reduced iron oxide combined with an alkali metal promoter supported on a solid catalyst support, such as sodium titanate, allows for RWGS reactions to produce carbon monoxide with selectivity of 90-100% and conversion of up to 60% at temperatures between 400°C to 600°C, reducing catalyst degradation and reactor damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional catalysts are used for RWGS reaction at high temperatures, then conversion of CO2 can be improved, but selectivity for CO decreases and side products like methane increase
Solution Approach 1:
The patent changes the oxidation state parameter of iron from +3 to less than +3 (reduced iron oxide), which fundamentally alters the catalytic behavior. This parameter change enables the catalyst to achieve both high CO2 conversion and high CO selectivity simultaneously, resolving the contradiction between productivity and manufacturing precision.
Solution Approach 2:
The patent creates a composite catalyst material combining reduced iron oxide with specific promoters (Cu, Zn, Al, La, Ce, Ti) on a supported structure. This composite approach allows the catalyst to achieve optimal balance between conversion and selectivity by synergistic effects of multiple components.
2Productivity
If high temperatures are used to increase CO2 conversion, then reaction rate improves, but catalyst degradation and reactor damage accelerate
Solution Approach 1:
By changing the iron oxidation state to less than +3, the catalyst becomes active at lower temperatures (400-600°C) compared to conventional high-temperature operation. This parameter change reduces thermal stress on both catalyst and reactor, improving reliability while maintaining productivity.
Solution Approach 2:
The patent introduces promoter elements (Cu, Zn, Al, La, Ce, Ti) as intermediaries that facilitate the reaction at lower temperatures. These promoters act as mediators that enable high reaction rates without requiring excessive temperature, thus protecting the catalyst and reactor from thermal degradation.
3Productivity
If thermal cycling is performed to optimize reaction conditions, then conversion can be improved, but catalyst degradation increases
Solution Approach 1:
The reduced iron oxide catalyst with oxidation state less than +3 operates stably at lower temperatures, reducing the severity of thermal cycling. This parameter change allows the catalyst to withstand temperature variations better, extending its operational lifetime while maintaining high conversion performance.
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 RWGS catalyst achieves stable performance for over 48 hours with high selectivity and conversion, suitable for integration into existing industrial infrastructure, and minimizes the production of side products like methane.
Implementation Method 1
The RWGS catalyst includes reduced iron oxide and an alkali metal promotor, which are both supported on a solid catalyst support
Implementation Method 2
precipitating a reduced iron oxide and an alkali metal promoter onto surfaces of a solid catalyst support through deposition reductive precipitation
Data Source
AI summary
A reverse water gas shift catalyst (RWGS catalyst) for conducting reverse water gas shift reactions to convert carbon dioxide to carbon monoxide includes reduced iron oxide and an alkali metal promoter supported on a solid catalyst support. The solid catalyst support includes a plurality of catalyst support particles, and the reduced iron oxide may have iron having an oxidation state of less than 3. Methods of making the RWGS catalyst and processes for converting carbon dioxide to carbon monoxide using the RWGS catalyst are also disclosed.