Gold-Modified Platinum Catalyst ORP Control
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Solution Overview
Problem
Existing methods for modifying platinum fine particle surfaces with gold to enhance catalyst durability are inefficient, as they lack precise control over gold deposition conditions, leading to uneven coverage and high costs, especially in large-scale production.
Innovation Solution
A method involving the adjustment of the oxidation-reduction potential (ORP) of a liquid medium to between −630 mV and +230 mV during gold reduction, using a reducing agent such as a branched-chain alcohol, to improve the coverage of platinum or platinum alloy surfaces with gold, ensuring selective deposition and enhanced catalyst durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If gold is deposited from a gold precursor by the action of a reducing agent to modify a platinum-supporting catalyst, then the durability of the catalyst is improved, but the platinum fine particle surface is not thoroughly covered with gold and gold is disadvantageously deposited in a region on the carrier surface where platinum fine particles are absent or in a solution
Solution Approach 1:
The patent applies parameter changes by controlling the ORP value within a specific range (−630 mV to +230 mV) to achieve uniform gold deposition on platinum surfaces. This parameter control ensures gold is deposited only where needed while preventing unwanted deposition in other regions, thereby resolving the contradiction between improving catalyst durability and achieving manufacturing precision.
2Ease of manufacture
If conventional gold deposition methods are used, then the process is simple, but the coverage of platinum surface with gold is insufficient and deposition is uneven
Solution Approach 1:
The patent introduces feedback control by monitoring and adjusting the ORP value during the gold deposition process. This feedback mechanism ensures that gold deposition proceeds uniformly across the platinum surface while maintaining process simplicity, thus resolving the contradiction between ease of manufacture and manufacturing precision.
3Manufacturing precision
If gold deposition is performed without ORP control, then the process is cost-effective, but the coverage and uniformity of gold on platinum surface are poor
Solution Approach 1:
The patent implements parameter changes by introducing ORP value control as a key parameter in the gold deposition process. This single parameter control achieves uniform gold coverage without significantly increasing device complexity, effectively resolving the contradiction between manufacturing precision and device complexity.
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 method significantly improves the coverage of platinum surfaces with gold, enhancing the durability and performance of catalysts used in fuel cells by optimizing gold deposition conditions, reducing costs, and ensuring uniformity in large-scale production.
Implementation Method 1
a step of gold reduction comprising adding carrier particles that support platinum or platinum alloys, a reducing agent, and a gold precursor to a liquid medium and mixing the same
Data Source
AI summary
This invention is intended to improve the coverage of a platinum or platinum alloy surface with gold when producing a catalyst comprising carrier particles that support gold-modified platinum or platinum alloys. The invention provides a method for producing a catalyst comprising carrier particles that support gold-modified platinum or platinum alloys comprising a step of gold reduction comprising adding carrier particles that support platinum or platinum alloys, a reducing agent, and a gold precursor to a liquid medium and mixing the same, wherein the reducing agent is added to adjust the ORP value (i.e., an oxidation-reduction potential with reference to the silver-silver chloride electrode) of the liquid medium to −630 to +230 mV upon completion of addition.