Cathodic Materials for Electrochemical Sensors Preventing Gas Crossover
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Solution Overview
Problem
Conventional fuel cells and electrochemical sensors using carbon supported noble metal catalysts, such as platinum, face issues like gas crossover leading to electrode degradation, reduced signal strength, and sensitivity loss due to contamination and oxidation, which affects their performance and longevity, especially in gas, smoke, and fire detectors.
Innovation Solution
The use of carbonaceous materials combined with oxygen reduction catalysts derived from pyrolysis of transition metal porphyrins and phthalocyanines, which act as supports and electron conductors, replacing traditional platinum-based electrodes, and configuring the anode and cathode on the same or opposite sides of an ion exchange membrane to prevent gas crossover.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If carbon supported noble metal catalysts (platinum) are used in electrochemical sensors, then catalytic activity for oxygen reduction is achieved, but gas crossover occurs leading to electrode degradation and sensitivity loss
Solution Approach 1:
The patent extracts platinum from the cathodic material formulation, eliminating the need for noble metal catalysts while maintaining catalytic activity through alternative materials such as carbonaceous materials with oxygen reduction catalysts derived from pyrolysis of transition metal porphyrins and phthalocyanines
Solution Approach 2:
The patent employs composite cathodic materials comprising carbonaceous materials combined with oxygen reduction catalysts from pyrolyzed transition metal porphyrins and phthalocyanines, creating a non-platinum-based composite that achieves both catalytic activity and resistance to gas crossover degradation
2Measurement precision
If conventional platinum-based electrodes are used, then high initial signal strength is achieved, but signal strength decreases over time due to contamination and oxidation
Solution Approach 1:
The patent replaces expensive platinum with cost-effective alternative materials that, while potentially having shorter theoretical lifetimes, provide sufficient operational longevity for sensor applications while being economically viable for replacement or regeneration
Solution Approach 2:
The patent uses composite cathodic materials with carbonaceous supports and pyrolyzed transition metal porphyrin/phthalocyanine catalysts that exhibit enhanced resistance to contamination and oxidation, thereby maintaining signal strength and measurement precision over extended operational periods
3Reliability
If anode and cathode are disposed on opposite sides of ion exchange membrane, then gas crossover is prevented, but device complexity increases
Solution Approach 1:
The patent designs cathodic materials that can function effectively in various electrode configurations (same side or opposite sides of membrane, same or different gaseous environments), making the sensor system more versatile and adaptable to different application requirements without compromising reliability
Solution Approach 2:
The patent modifies the chemical and physical parameters of cathodic materials to achieve optimal performance across different operational configurations, enabling flexibility in electrode placement and environmental exposure while maintaining sensor reliability
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
This configuration enhances the stability and sensitivity of electrochemical sensors by preventing gas crossover, reducing electrode degradation, and maintaining signal strength over time, while also offering a cost-effective alternative to platinum-based catalysts.
Implementation Method 1
an ion exchange membrane, wherein the anode and the cathode are disposed upon the same side or different sides of the ion exchange membrane
Implementation Method 2
a carbonaceous material and an oxygen reduction catalyst associated with the carbonaceous material
Implementation Method 3
an oxygen reduction catalyst associated with the carbonaceous material
Implementation Method 4
cathodic materials for use in electrochemical sensors... associated with oxygen reduction catalysts
Implementation Method 5
oxygen reduction catalysts derived from pyrolysis of transition metal porphyrins and phthalocyanines
Data Source
AI summary
A cathodic material for use in an electrochemical sensor comprising: a carbonaceous material and an oxygen reduction catalyst associated with the carbonaceous material; and wherein the cathodic material does not materially exhibit catalytic activity for the oxidation of carbon monoxide. Associated electrochemical sensors may include an anode and cathode that are disposed upon the same or opposite sides of an ion exchange membrane and/or exposed to the same or different gaseous environments.