Buffered Cobalt Oxide Catalysts for Low Overpotential Electrolysis
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Solution Overview
Problem
Current water electrolysis technologies are energy inefficient and commercially impractical for converting renewable energy into hydrogen gas due to high overpotential requirements and limitations in catalyst stability and availability, especially for cobalt oxide systems that operate in strongly basic media.
Innovation Solution
A method using an anode with a catalytic coating of cobalt, oxygen, and a fluoride anion in an aqueous solution at a pH between 3 and 6.8, which facilitates the generation of oxygen and hydrogen with reduced overpotential, stability, and availability of cobalt and fluoride anions, allowing for efficient electrolysis at ambient conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If cobalt oxide catalysts are used in strongly basic media for water electrolysis, then catalytic activity is improved, but the catalyst degrades under reaction conditions and requires elevated temperatures
Solution Approach 1:
The patent changes the pH parameter from strongly basic to neutral or acidic conditions, allowing cobalt oxide catalysts to function without degrading. This parameter change enables the catalyst to operate stably at ambient temperatures while maintaining activity, resolving the contradiction between catalytic performance and stability.
Solution Approach 2:
The patent introduces a protective coating or support structure as an intermediary between the cobalt oxide catalyst and the electrolyte environment. This intermediary protects the catalyst from degradation while allowing it to maintain its catalytic function under neutral or acidic conditions.
2Loss of energy
If specialized anodes with catalysts are used to reduce overpotential, then energy efficiency is improved, but the catalysts are not widely available at reasonable cost
Solution Approach 1:
The patent employs cobalt oxide catalysts that can be deposited on inexpensive substrate materials such as graphite or metal foils. These substrates serve as cost-effective carriers that enable the use of relatively small amounts of cobalt oxide, making the overall catalyst system more affordable and widely available while maintaining low overpotential.
Solution Approach 2:
The patent creates composite catalyst structures by combining cobalt oxide with inexpensive substrate materials or supporting structures. This composite approach maintains the high catalytic activity of cobalt oxide while the inexpensive components provide structural support and reduce overall material costs, improving both performance and affordability.
3Productivity
If cobalt oxide coatings are applied to anodes in fluoborate electrolyte, then some catalytic function is achieved, but the overpotential concern is not adequately addressed
Solution Approach 1:
The patent optimizes the pH parameter of the electrolyte to neutral or acidic values, which significantly reduces the overpotential required for the oxygen evolution reaction. This parameter change enhances the catalytic efficiency of cobalt oxide coatings, addressing the overpotential issue while maintaining catalytic function.
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 method achieves efficient generation of hydrogen and oxygen with low overpotential rise at increasing current densities, stability under oxidizing conditions, and availability of materials at low cost, making the process more commercially viable for storing renewable energy.
Implementation Method 1
anode with a catalytic coating of cobalt, oxygen, and a fluoride anion... facilitates the generation of oxygen and hydrogen with reduced overpotential
Implementation Method 2
A method using an anode with a catalytic coating of cobalt, oxygen, and a fluoride anion in an aqueous solution at a pH between 3 and 6.8, which facilitates the generation of oxygen and hydrogen
Implementation Method 3
aqueous solution adjacent the anode has water, cobalt cation and an anion (e.g. fluoride) electrolyte
Data Source
AI summary
Disclosed are electrolysis catalysts formed from cobalt, oxygen and buffering electrolytes (e.g. fluoride). They can be formed as a coating on an anode by conducting an electrolysis reaction using an electrolyte containing cobalt and an anionic buffering electrolyte. The catalysts will facilitate the conversion of water to oxygen and hydrogen gas at a range of mildly acidic conditions. Alternatively, these anodes can be used with cathodes that facilitate other desirable reactions such as converting carbon dioxide to methanol.