Gas Diffusion Electrode for Monodisperse Metal Nano Crystal Recovery

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current methods for recovering critical metals like rare earth elements from aqueous solutions are economically inefficient and fail to produce crystalline nano particles with controlled size distribution, particularly those smaller than 50 nm, which are essential for advanced technological applications.

Innovation Solution

An electrochemical process involving a gas diffusion electrode with a porous electrochemically active material, where the pH of the catholyte is adjusted below the pKa of the precursor compound, and an oxidant gas is supplied to induce redox transformation, forming nano particles with an average size of 30 nm or smaller by reducing oxidant gases to peroxide and radical species that react with metal ions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional electrochemical methods are used to produce nano crystals, then the process is simple and widely applicable, but the particle size distribution becomes highly polydisperse and nonuniform

Engineering Contradiction:

Improvesimplicity of electrochemical processVSAvoiduniformity of particle size distribution

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies local quality by introducing a cathode with specific local properties (gas diffusion electrode, porous structure, high surface area) that creates localized conditions for uniform nucleation and growth. The cathode structure and surface characteristics are optimized to ensure uniform distribution of reduction sites, thereby producing monodisperse nano crystals despite the simplicity of the overall electrochemical process.

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If chemical methods with crystal seeding are used, then particle growth control is improved, but the process becomes more complex and requires multiple inseparable steps

Engineering Contradiction:

Improvecontrol of particle growthVSAvoidnumber of process steps

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent merges multiple functions into a single electrochemical process step. The cathode simultaneously performs nucleation, growth, and size control functions that would traditionally require separate chemical steps including seeding, growth promotion, and termination. The gas diffusion electrode structure integrates these functions, allowing monodisperse nano crystal formation in one operation without requiring multiple inseparable process steps.

Inventive Principle:

Principle #5Merging (Combining)

3Ease of manufacture

If physical methods are used to synthesize nano particles, then the process is straightforward, but milder reaction conditions cannot be achieved

Engineering Contradiction:

Improvesimplicity of synthesis methodVSAvoidreaction condition mildness

Core Design Contradiction:

Ease of manufactureVSTemperature

Solution Approach 1:

The patent replaces physical methods with an electrochemical mechanism that operates under milder conditions. Instead of relying on high energy physical processes, the invention uses controlled electrochemical reduction at the cathode surface, enabling synthesis at lower temperatures and energies while maintaining process simplicity. The electrochemical approach provides a straightforward mechanism that achieves mild reaction conditions without compromising manufacturing simplicity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 process achieves high recovery rates of metal ions, exceeding 99% efficiency, producing crystalline nano particles with a narrow size distribution suitable for various technological applications, including electronics and cosmetics.

Implementation Method 1

induce redox transformation, forming nano particles with an average size of 30 nm or smaller by reducing oxidant gases to peroxide and radical species that react with metal ions

Methodology Applied

Scientific EffectRedox transformation: Redox Reactions

Implementation Method 2

electrochemical process involving a gas diffusion electrode with a porous electrochemically active material, where the pH of the catholyte is adjusted below the pKa of the precursor compound

Methodology Applied

Scientific EffectElectrochemical reduction: Electrolysis

Data Source

PatentEP3242963B1An electrochemical process for preparing a reaction product of a metal or metalloid element

Publication Date: 2018.09.26 VLAAMSE INSTELLING VOOR TECHNOLOGISCH ONDERZOEK NV (VITO)

Figure 1a
Figure 1b
Figure 2

AI summary

The present invention relates to an electrochemical process for recovering a metal element or a metalloid element or a mixture of two or more thereof from at least one water soluble precursor compound comprising the metal element or a metalloid element or two or more thereof, in the form of one or more nano particles, in particular nano crystals of at least one reaction product. The process comprises the steps of supplying the water soluble precursor compound to a water-based catholyte of a cathode compartment of an electrochemical cell, equipped with a cathode comprising a gas diffusion electrode, adjusting the pH of the catholyte, supplying at least one oxidant gas to the gas diffusion electrode, subjecting the cathode to an electrochemical potential to cause reduction of the at least one oxidant gas.