Anion-Exchange Electrode Material for Low-CO2 Electrolysis

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Solution Overview

Problem

Existing CO2 reduction technologies face challenges in retaining CO2 near the catalyst at low concentrations, leading to reduced production efficiency and increased side reactions due to the use of acidic cation exchange resins, which are permeable to metal ions and lack CO2 adsorption ability.

Innovation Solution

Employing a catalyst-supported conductive carrier coated with an anion exchange resin having a basic site density of 2.0 to 5.0 mmol/cm3, utilizing primary, secondary, or quaternary ammonium groups to enhance CO2 adsorption and reduce side reactions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a cation exchange resin is used as an electrode material, then ion conductivity is improved, but CO2 adsorption ability deteriorates and side reactions increase

Engineering Contradiction:

Improveion conductivityVSAvoidside reactions and lack of CO2 adsorption

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent inverts the conventional approach by using an anion exchange resin instead of a cation exchange resin for CO2 reduction. This inversion allows the resin to adsorb CO2 through its basic sites while maintaining ion conductivity, thereby eliminating the trade-off between ion conductivity and CO2 adsorption ability that plagues cation exchange resins

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent optimizes the basic site density of the anion exchange resin to a specific range (2.0 to 5.0 mmol/cm³) to achieve the best balance between CO2 adsorption capacity and ion conductivity. This parameter optimization ensures high CO2 reduction efficiency while preventing excessive salt deposition

Inventive Principle:

Principle #35Parameter changes

2Quantity of substance

If CO2 concentration is low, then CO2 supply to catalyst is reduced, but retaining CO2 near catalyst becomes difficult

Engineering Contradiction:

ImproveCO2 concentrationVSAvoidCO2 reduction efficiency

Core Design Contradiction:

Quantity of substanceVSProductivity

Solution Approach 1:

The anion exchange resin performs preliminary CO2 adsorption before the CO2 reaches the catalyst surface. By pre-concentrating CO2 on the resin's basic sites, the system ensures sufficient CO2 availability at the catalyst even when bulk CO2 concentration is low, thereby maintaining high reduction efficiency

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The anion exchange resin acts as an intermediary between the CO2 supply and the catalyst. It adsorbs CO2 from the bulk phase and facilitates its transfer to the catalyst surface, effectively mediating the CO2 supply process and overcoming the limitation of low CO2 concentration

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If cation exchange resin is used, then ion permeability is improved, but metal ion deposition increases

Engineering Contradiction:

Improveion permeabilityVSAvoidmetal ion deposition

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

The patent switches from cation exchange resin to anion exchange resin, which reverses the ion selectivity. The anion exchange resin preferentially conducts anions (OH⁻, HCO3⁻) while repelling metal cations, thereby maintaining ion permeability while preventing metal ion deposition that plagues cation exchange resins

Inventive Principle:

Principle #13The other way round (Inversion)

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

Improves CO2 reduction efficiency, especially at low CO2 concentrations, by effectively adsorbing and converting CO2 into hydrogen carbonate ions, maintaining high catalytic activity, and minimizing ion permeation and side reactions.

Implementation Method 1

a compound having a property of interacting with CO2 by adsorption or the like is co-supported on electrodes together with a catalyst to increase the adsorption amount of weakly acidic CO2

Methodology Applied

Scientific EffectAdsorption: Adsorption

Implementation Method 2

CO2 reduction device having the polymer electrolyte-type electrolytic cell

Methodology Applied

Scientific EffectElectrochemical reduction: Electrolysis

Data Source

PatentUS12435430B2Electrode material, membrane electrode assembly, CO<sub>2 </sub>electrolysis device, and method for producing CO<sub>2 </sub>electrolysis product

Publication Date: 2025.10.07 IDEMITSU KOSAN CO LTD

AI summary

An electrode material containing a carrying body and an anion exchange resin. The carrying body includes a conductive carrier and a catalyst, the catalyst is supported on the conductive carrier, and the catalyst includes one or a plurality of particles selected from a metal complex, a metal, and an inorganic compound. The anion exchange resin covers a part or all of a surface of the carrying body, the anion exchange resin includes an ionomer containing one or a plurality of groups selected from a primary amino group, a secondary amino group, a tertiary amino group, and a quaternary ammonium group, and a basic site density of the ionomer is 2.0 mmol/cm3 or more and 5.0 mmol/cm3 or less.