Hybrid Anode Catalyst Composition for CO Tolerance and Corrosion Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fuel cells face challenges during cell reversal events and in the presence of CO, leading to anode catalyst degradation, carbon corrosion, and reduced fuel cell lifetime, with existing solutions like air bleeding causing long-term cell degradation.
Innovation Solution
A hybrid electrocatalyst material is developed with Pt-based anode catalysts and a second catalytic particle, such as iridium or Pd-alloy, dispersed on individual support particles or aggregates, maintaining high surface area and proximity to enhance durability and CO tolerance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If air bleeding is used to prevent CO poisoning, then CO tolerance is improved, but long-term cell degradation occurs
Solution Approach 1:
The invention extracts and removes the harmful CO component from the fuel stream using a dedicated CO removal layer containing specific catalysts (Pd, Au, or their alloys) that selectively oxidize CO to CO2, thereby eliminating the need for air bleeding and preventing long-term cell degradation while maintaining CO tolerance
Solution Approach 2:
The invention introduces an intermediary CO removal layer between the fuel supply and the Pt-containing catalyst layer. This intermediate layer acts as a filter that selectively removes CO through catalytic oxidation before the fuel reaches the main catalyst, preventing CO poisoning without requiring air bleeding that causes degradation
2Productivity
If Pt-containing catalysts are used at the anode, then electrocatalytic activity is improved, but carbon corrosion occurs during cell reversal events
Solution Approach 1:
The invention applies preliminary protective action by incorporating corrosion-resistant metals (Ir, Ru, Rh, or their alloys) in the CO removal layer and/or Pt alloy structures that preemptively prevent carbon corrosion during cell reversal events, countering the harmful oxidative effects before they can damage the carbon support and Pt catalyst
Solution Approach 2:
The invention uses composite catalyst structures combining Pt with corrosion-resistant metals (forming Pt alloys) and composite layer structures (CO removal layer + catalyst layer) that integrate both high electrocatalytic activity and enhanced corrosion resistance, maintaining catalyst stability during cell reversal while preserving productivity
3Productivity
If catalyst loading is increased to improve performance, then electrocatalytic activity is improved, but cost increases
Solution Approach 1:
The invention applies local quality by concentrating corrosion-resistant metals (Ir, Ru, Rh, or their alloys) specifically in the CO removal layer where CO oxidation occurs, rather than distributing them uniformly throughout the catalyst layer. This localized placement provides targeted protection and CO removal functionality while minimizing the total amount of expensive noble metals required, thus reducing cost while maintaining high electrocatalytic activity
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 hybrid electrocatalyst material improves fuel cell performance and durability by preventing carbon corrosion during fuel starvation and reducing CO poisoning, allowing for extended operation without the need for air bleeding, thus enhancing catalyst stability and fuel cell lifetime.
Implementation Method 1
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 2
the water oxidation catalyst can act to prevent carbon corrosion events. Due to the close proximity of the active Pt-containing particles and the water oxidation catalyst particles, corrosion of the catalyst support particles can be prevented or reduced significantly
Implementation Method 3
the third particles comprise Au or a third metal alloy... in close proximity to the active Pt-containing particles, thereby freeing up active sites on the Pt-containing particles for hydrogen oxidation
Data Source
AI summary
The use of an electrocatalyst material in an anode catalyst layer, wherein the electrocatalyst material comprises a support material, the support material comprising a plurality of individual support particles or aggregates wherein each individual support particle or aggregate has dispersed thereon (i) first particles and (ii) second particles, wherein: (i) the first particles comprise Pt optionally alloyed with an alloying metal X1; wherein the optional alloying metal X1 is selected from the group consisting of Rh, Ti, Os, V, Co, Ni, Ga, Hf, Sn, Ir, Pd, Mo, Zn, W, Zr and Re; (ii) the second particles consist essentially of a second metal or a second metal compound wherein the second metal is selected from the group consisting of Ir and Ru and the second metal compound comprises IrX2 wherein X2 is selected from the group consisting of Ta, Nb, Ru, Ni and Co; and wherein if the first particles consist of Pt then the second particles do not comprise IrTa; and wherein if the first particles consist of Pt without alloying metal X1 and the second particles consist essentially of a second metal which is Ir, each individual support particle or aggregate of the support material of the electrocatalyst material has dispersed thereon only the said first and second particles; or wherein each individual support particle or aggregate has dispersed thereon (i) first particles and (ii) third particles, wherein: (iii) the third particles comprise Au or a third metal alloy; wherein the third metal alloy is selected from the group consisting of AuX3 and PdX4, wherein X3 is selected from the group consisting of Pt, Pd, Cu, Ir and Sn; and X4 is selected from the group consisting of Hg, Au, Sn, Co, Ni, Ga, In, Zn, W and Pb.