CO2 Reduction Catalyst with Quaternary Nitrogen Cation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current technologies for artificial photochemical CO2 reduction using a Z-scheme system have low solar energy conversion efficiency due to interconnection resistance and require sacrificial reagents, limiting the efficiency of CO2 reduction reactions.
Innovation Solution
A CO2 reduction catalyst is developed with a charge collector, an organic molecular layer, and metal fine particles, where modified organic molecules with a quaternary nitrogen cation are bound to the metal surface, enhancing the CO2 reduction reaction efficiency by increasing the reactive area and reducing energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a Z-scheme-type artificial photosynthesis system with electrodes connected by electric wire is used, then CO2 reduction reaction can proceed, but solar energy conversion efficiency becomes very low due to interconnection resistance
Solution Approach 1:
The patent extracts and eliminates the electric wire interconnection from the system, replacing it with a direct liquid junction between oxidation and reduction compartments. This removes the source of interconnection resistance and enables efficient charge transfer without wiring losses.
Solution Approach 2:
The patent introduces an ion-exchange membrane as an intermediary component that facilitates ion transport between compartments while maintaining electrical neutrality. This mediator enables efficient charge balance without requiring direct electronic connection, thus avoiding resistance losses.
2Productivity
If photocatalyst excited by optical wavelength is used, then photochemical reaction can occur, but energy efficiency becomes low
Solution Approach 1:
The patent segments the photochemical system into separate oxidation and reduction compartments, each with dedicated catalysts. This allows optimization of each half-reaction independently and enables better matching of photon absorption to specific catalytic functions, improving overall energy efficiency.
Solution Approach 2:
The patent changes the operational parameters by using visible light irradiation combined with specific catalyst compositions (Ru(bpy)3^2+ for oxidation, Au or Pt for reduction) and controlled potential application. This combination optimizes the energy utilization of the photocatalyst system.
3Loss of energy
If plate-like laminated structure with silicon solar cell is used, then solar energy conversion efficiency increases and size can be increased easily, but CO2 reduction reaction fails due to lack of ion movement capability
Solution Approach 1:
The patent introduces ion-exchange membranes as intermediaries that enable ion transport between compartments. This mediator system provides the necessary ionic conductivity that was missing in the plate-like structure, allowing CO2 reduction to proceed while maintaining high solar energy conversion efficiency.
Solution Approach 2:
The patent applies different functional qualities to different regions: ion-exchange membranes in compartments requiring ion transport, and solid polymer electrolytes in regions requiring both ion conduction and structural support. This localized application of appropriate materials enables both efficient CO2 reduction and high energy conversion.
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 achieves high CO2 reduction efficiency by increasing the reactive area and selectively advancing the CO2 reduction reaction with low energy consumption, producing carbon monoxide, formic acid, and other hydrocarbons effectively.
Implementation Method 1
a multi-junction solar cell which generates photoexcited electrons by absorbing light energy
Implementation Method 2
Due to a photochemical reaction in such a system, plants oxidize water (H2O) to obtain electrons
Implementation Method 3
an electrode for a reduction reaction which is provided with a reduction catalyst for reducing CO2
Data Source
AI summary
According to one embodiment, a reduction catalyst includes a charge collector having a metal layer on a surface; and a modified organic molecule bound to a surface of the metal layer and containing a quaternary nitrogen cation.