Multilayer Catalyst Substrate for Fuel Cell Noble Metal Loss Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fuel cell technologies face high noble-metal catalyst loss and inefficient catalyst utilization due to aggregation of fine catalyst metal particles, limiting the spread and performance of polymer fuel cells.
Innovation Solution
A process involving alternating layers of a mixture of first and second pore-forming metals or fibrous carbon is deposited on a substrate by sputtering or vapor deposition, followed by a pore formation step to create a multilayer structure with micropores and interstices, enhancing catalyst metal utilization efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If a noble-metal catalyst slurry is applied to a substrate to produce electrodes, then the electrode can be formed with catalyst metal, but the noble-metal loss in the process is as large as about 30%
Solution Approach 1:
The patent replaces the conventional slurry application method (mechanical/chemical process) with physical vapor deposition methods (sputtering or vapor deposition). This substitution eliminates the need for slurry processing, thereby reducing noble-metal loss to minimal levels while maintaining electrode production capability.
Solution Approach 2:
The patent changes the physical state and deposition parameters of the catalyst metal from liquid slurry to vapor phase deposition. By controlling deposition parameters such as sputtering power, gas flow rate, and substrate temperature, the catalyst metal is deposited directly as a thin film, achieving near-zero loss compared to the 30% loss in slurry methods.
2Reliability
If a catalyst metal layer is sputtered on a substrate and a layer of particulate carbon is formed thereon, then the catalyst layer can be produced, but fine catalyst metal particles aggregate to form large particles, resulting in an insufficient efficiency of catalyst metal utilization
Solution Approach 1:
The patent segments the catalyst layer into multiple thin alternating layers of catalyst metal and porous support material (such as titanium oxide or silicon oxide) rather than forming a single continuous layer. This segmentation prevents particle aggregation by distributing the catalyst metal into discrete thin layers separated by porous intermediaries, maintaining fine particle morphology and high utilization efficiency.
Solution Approach 2:
The patent introduces a porous support material layer (titanium oxide, silicon oxide, or other oxides) as an intermediary between the catalyst metal layers. This intermediary layer prevents direct contact and aggregation of catalyst metal particles while providing a porous structure that enhances surface area and catalyst dispersion, thereby maintaining fine particle size and high utilization efficiency.
3Reliability
If an easy-to-dissolve metal is used as a pore-forming metal to form an alloy or mixture thereof with a catalyst metal by sputtering or vapor deposition and a porous structure is thereafter formed in the resultant catalyst layer by a pore formation process, then a porous catalyst layer can be produced, but the efficiency of catalyst utilization is insufficient
Solution Approach 1:
The patent extracts and removes the porous support material layers (titanium oxide, silicon oxide, or other oxides) after the multilayer structure is formed, creating a porous catalyst layer structure. This extraction process, followed by acid treatment to remove the support material, generates a hierarchical porous structure that enhances catalyst utilization efficiency while simplifying the overall process compared to traditional pore-forming methods.
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 approach improves catalyst metal utilization efficiency and enables the production of high-power fuel cells with reduced noble-metal usage, maintaining performance while minimizing catalyst particle aggregation.
Implementation Method 1
at least one first pore-forming metal and at least one catalyst metal are sputtered or vapor-deposited on a substrate to form a mixture layer
Implementation Method 2
at least one first pore-forming metal and at least one catalyst metal are sputtered or vapor-deposited on a substrate to form a mixture layer
Implementation Method 3
the first and second pore-forming metals in the multilayer structure are dissolved away to obtain a catalyst layer
Data Source
AI summary
A catalyst-layer-supporting substrate comprising a substrate supporting a catalyst layer; wherein the catalyst layer comprises two or more porous catalyst metal particle layers that are superposed alternately with (i) two or more intersticed layers comprising at least one element selected from the group consisting of Mn, Fe, Co, Ni, Zn, Sn, Al, and Cu; or (ii) two or more fibrous carbon layers having interstices among fibers of the fibrous carbon. A method for forming a catalyst-layer-supporting structure that comprises porous catalyst metal particle by removing a pore-forming metal from a mixture layer containing a pore-forming metal and a catalyst metal.