Electrolysis Anode Coating for Low Oxygen By-Product
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional anodes for electrolysis by the ion exchange membrane process face issues with long-term stability, selective consumption of platinum, passivation, and insufficient durability, leading to high costs and low purity of chlorine gas due to high concentrations of by-product oxygen and overvoltage.
Innovation Solution
An anode comprising a substrate with multiple coating layers of iridium oxide, ruthenium oxide, and titanium oxide, followed by a platinum-iridium oxide layer, applied using the thermal decomposition baking method and post-baked at higher temperatures to enhance adherence and reduce by-product oxygen concentration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If conventional anodes with platinum component are used, then by-product oxygen gas evolution is reduced, but long-term stability deteriorates due to selective consumption of platinum and passivation
Solution Approach 1:
The patent applies composite materials by creating a multi-layer coating structure where a platinum-iridium oxide mixture layer is combined with a manganese oxide-titanium oxide layer. This composite structure allows the platinum component to reduce oxygen evolution while the manganese oxide-titanium oxide layer prevents selective consumption and passivation, achieving both low oxygen concentration and long-term stability
Solution Approach 2:
The patent applies local quality by distributing different functional materials in specific layers: the platinum-iridium oxide mixture is localized in the first coating layer to suppress oxygen evolution, while the manganese oxide-titanium oxide mixture is localized in the second coating layer to provide stability and prevent platinum consumption, with each layer performing its specific function
2Object-generated harmful factors
If platinum component is applied to reduce by-product oxygen, then oxygen evolution is suppressed, but manufacturing cost increases due to platinum consumption and replacement
Solution Approach 1:
The patent applies this principle by using a sacrificial protective layer of manganese oxide-titanium oxide that is less valuable than platinum. This layer is designed to be consumed or degraded first, protecting the expensive platinum layer underneath, thereby reducing overall platinum consumption while maintaining the oxygen suppression function
Solution Approach 2:
The composite structure combines expensive platinum-iridium oxide with cheaper manganese oxide-titanium oxide, allowing the system to achieve the desired performance with reduced platinum content while the cheaper materials provide protective and stabilizing functions
3Ease of manufacture
If thermal decomposition baking method is used, then coating layers are formed, but adherence is insufficient without post-baking treatment
Solution Approach 1:
The patent applies preliminary action by first forming the coating layers through thermal decomposition baking, then performing an additional post-baking treatment at higher temperature. This sequential approach allows the coating to be initially formed and then subsequently strengthened, achieving both ease of manufacture and high adherence
Solution Approach 2:
The patent applies parameter changes by changing the thermal treatment parameters - first applying thermal decomposition baking at a certain temperature to form the coating, then performing post-baking at a higher temperature to enhance adherence, using temperature parameter changes to achieve different functional outcomes
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 anode with low chlorine overvoltage and high oxygen overvoltage, reducing the dissolution of platinum group metals and eliminating the need for large hydrochloric acid dosing, resulting in high-purity chlorine gas production.
Implementation Method 1
coating layers provided by the thermal decomposition baking method on the surface of the substrate
Implementation Method 2
the coating layer is followed by post-baking at a higher baking temperature than the formerly applied in the thermal decomposition baking method
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention aims to provide an anode for electrolysis by an ion exchange membrane process and the manufacturing method thereof which can show a lower concentration of by-product oxygen gas in chlorine gas and a lower overvoltage stably for a long time, compared with conventional anodes. Solution to problem The present invention is to prepare an anode for electrolysis, comprising a substrate comprising titanium or titanium alloy and a plurality of coating layers provided by the thermal decomposition baking method on the surface of the substrate, wherein the coating layer comprises the first coating layer comprising a mixture of iridium oxide, ruthenium oxide and titanium oxide, provided on the surface of the substrate, the second coating layer comprising a mixture of platinum and iridium oxide, provided on the first coating layer, a unit layer comprising the first coating layer and the second coating layer, provided on the surface of the second coating layer by a single or a plurality of layer, and the second coating layer, provided on the outermost layer of the unit layer; the plurality of layer is provided on the surface of the substrate by means of the thermal decomposition baking method and the coating layer is followed by post-baking at a higher baking temperature than the formerly applied in the thermal decomposition baking method.