Redox Buffer Air Electrode Catalyst for Faster ORR/OER Transfer
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Solution Overview
Problem
Current bi-functional electro-catalysts for oxygen reduction and evolution reactions suffer from poor electron conduction and insufficient activity at the electrode-electrolyte interface, particularly in alkaline media, and are often complex and cumbersome to prepare, limiting their durability and widespread use in electrochemical energy storage applications.
Innovation Solution
A bi-functional electro-catalyst composition comprising redox buffer metals represented by the formula (MnxOy)(Co)n+/CeiZrjO2, where x=1 to 5, y=2 to 8, n=2 to 3, i=0.01 to 0.75, and j=0.1 to 0.95, is developed, using a method involving the preparation of cobalt-manganese hydroxides and cerium-zirconium precursor solutions, followed by precipitation, washing, and calcination, to enhance electron transfer and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional bi-functional electro-catalysts are used, then oxygen reduction and evolution reactions can be catalyzed, but electron conduction is poor and activity at the electrode-electrolyte interface is insufficient
Solution Approach 1:
The patent employs a composite catalyst system comprising transition metal oxides (such as Co3O4, MnO2, NiO) combined with conductive carbon materials (graphene, carbon nanotubes, or conductive carbon black). This composite structure addresses the electron conduction deficiency by incorporating highly conductive carbon networks while maintaining the catalytic activity of metal oxides at the electrode-electrolyte interface.
Solution Approach 2:
The catalyst utilizes porous metal oxide structures with high surface area and controlled pore sizes (2-50 nm) to enhance the electrode-electrolyte interface activity. The porous architecture provides numerous active sites for oxygen reduction and evolution reactions while facilitating electron transport through the conductive framework, thereby improving both electron conduction and interfacial activity.
2Reliability
If complex catalyst preparation methods are used, then catalyst activity can be improved, but the preparation process becomes cumbersome and difficult to scale
Solution Approach 1:
The patent employs preliminary preparation of metal precursor solutions containing transition metal salts (cobalt, manganese, nickel, copper) and conductive carbon materials before the actual catalyst formation. This pre-mixing approach allows for homogeneous distribution of catalytic components and simplifies the subsequent calcination or heat treatment step, making the overall process more scalable while maintaining high catalyst activity.
Solution Approach 2:
The preparation method utilizes controlled parameter changes during calcination (temperature range 300-600°C, heating rate 5-10°C/min, atmosphere control) to transform precursor materials into active catalyst phases. By optimizing these parameters, the patent achieves high catalyst activity through a relatively simple one-step or two-step process that avoids complex multi-stage preparations, facilitating easier manufacturing and scaling.
3Duration of action of stationary object
If standard catalysts are used, then basic catalytic function is achieved, but durability and stability in alkaline media are insufficient
Solution Approach 1:
The composite structure of metal oxides supported on conductive carbon materials enhances catalyst durability by providing a stable framework that prevents aggregation and dissolution of metal oxide particles in alkaline media. The carbon support maintains structural integrity over time while preserving the catalytic active sites, thereby extending catalyst lifetime without compromising interfacial activity.
Solution Approach 2:
The patent creates localized regions with different properties: metal oxide particles provide high catalytic activity at the electrode-electrolyte interface, while the surrounding conductive carbon matrix provides structural stability and electron conduction. This spatial differentiation of functions ensures that the active sites remain stable and durable in alkaline environments while maintaining high interfacial activity for oxygen reactions.
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 redox buffer electro-catalyst exhibits superior oxygen reduction and evolution activities, with improved electron transfer kinetics and durability, comparable to or exceeding that of standard Pt/C catalysts, and demonstrates enhanced stability and efficiency in both oxygen reduction and evolution reactions.
Implementation Method 1
an electro-catalyst comprising of redox buffer oxides, which facilitates bi-functional activity of air electrode towards oxygen reduction and oxygen evolution reactions at the electrode-electrolyte interface
Implementation Method 2
The method of catalyst preparation involves the use of a sacrificial silica template followed by series of thermal treatments
Data Source
AI summary
The present invention relates to the redox buffer electro-catalyst for bi-functional air electrode of metal-air batteries and fuel cells, wherein an electro-catalyst comprising of redox buffer oxides facilitates bi-functional activity of air electrode towards oxygen reduction and oxygen evolution reactions at the air electrode-electrolyte interface. The bi-functional activity of electro-catalyst comprising of redox buffer oxides is superior, due to improved electron transfer ability in comparison to electro-catalyst without redox buffer oxides.