Polymer-Supported Catalyst Layer to Mitigate Carbon Corrosion
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Solution Overview
Problem
Fuel cells face durability issues due to high electrochemical potentials from cell reversal and start-up shut-down events, leading to carbon corrosion and performance degradation, especially in automotive applications where low platinum loading is required for commercial viability.
Innovation Solution
A catalyst layer comprising platinum-containing electrocatalyst, oxygen evolution reaction electrocatalyst, and highly conductive, corrosion-resistant carbonaceous materials like graphite, nanofibres, and heat-treated carbon blacks, which do not support the platinum, combined with a proton-conducting polymer, to enhance durability and reduce platinum loading.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If carbon supported platinum catalyst is used, then catalyst activity is improved, but carbon corrosion occurs during high voltage events leading to durability degradation
Solution Approach 1:
The patent removes the platinum catalyst from direct contact with carbon support materials by using a proton-conducting polymer electrolyte as the catalyst support instead. This extraction of platinum from the carbon-supported configuration eliminates the carbon corrosion pathway while maintaining catalytic activity through the polymer-supported platinum structure.
Solution Approach 2:
The patent employs a composite material system consisting of platinum particles dispersed within a proton-conducting polymer electrolyte matrix. This composite structure provides both the catalytic activity of platinum and the corrosion resistance of the polymer, creating a durable catalyst layer that withstands high voltage events without carbon degradation.
2Quantity of substance
If platinum loading is reduced for commercial viability, then cost is reduced, but catalyst performance and durability may deteriorate
Solution Approach 1:
The patent changes the physical and chemical parameters of the catalyst support from carbon-based materials to proton-conducting polymer electrolytes. This parameter change enables reduced platinum loading while maintaining performance because the polymer matrix provides better platinum utilization efficiency and stability, allowing commercial viability without sacrificing catalyst reliability.
3Adaptability or versatility
If high electrochemical potentials occur during cell reversal or start-up shut-down, then real-life operational flexibility is improved, but carbon corrosion and performance degradation occur
Solution Approach 1:
The patent implements beforehand cushioning by using a proton-conducting polymer electrolyte that inherently resists oxidation and corrosion. This protective polymer matrix cushions the platinum catalyst against the harmful effects of high electrochemical potentials during cell reversal or start-up shut-down events, allowing operational flexibility without performance degradation.
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 solution provides a durable and uniformly coated catalyst layer with reduced platinum loading, effectively mitigating carbon corrosion and maintaining performance during high voltage events, thereby enhancing the commercial viability of fuel cells for automotive use.
Implementation Method 1
In the proton exchange membrane fuel cell (PEMFC) the membrane is proton conducting, and protons, produced at the anode, are transported across the membrane to the cathode
Implementation Method 2
Electrocatalysts are used to promote the electrochemical oxidation of the fuel at the anode and the electrochemical reduction of oxygen at the cathode. Electrocatalysts are used to promote the electrochemical oxidation of the fuel at the anode and the electrochemical reduction of oxygen at the cathode
Implementation Method 3
Electrocatalysts are used to promote the electrochemical oxidation of the fuel at the anode and the electrochemical reduction of oxygen at the cathode
Implementation Method 4
Therefore the gas diffusion layer must be porous and electrically conducting
Data Source
AI summary
A catalyst layer comprising: (i) a platinum-containing electrocatalyst; (ii) oxygen evolution reaction electrocatalyst; (iii) one or more carbonaceous materials selected from the group consisting of graphite, nanofibres, nanotubes, nanographene platelets and low surface area, heat-treated carbon blacks wherein the one or more carbonaceous materials do not support the platinum-containing electrocatalyst; and (iv) proton-conducting polymer and its use in an electrochemical device is disclosed.