Co3O4@IrOx Catalyst with Vacancy Anchoring for Low-Ir Water Electrolysis
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Solution Overview
Problem
Current methods for preparing Ir-doped oxygen evolution electrocatalysts face challenges such as high costs, complex processing, poor reproducibility, and low stability, necessitating a simple and scalable method for improving catalytic efficiency and reducing Ir dosage.
Innovation Solution
A Co3O4@IrOx catalyst is synthesized using a ZIF-67@ZIF-8 core-shell material, where ZIF-67 is pyrolyzed to Co3O4, and pulsed potential etching and electrochemical deposition are used to create defects and anchor Ir atoms, forming a strong coupling interface with a nitrogen-doped porous carbon framework.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If precious metal materials such as IrO2 and RuO2 are used in PEM electrolyzers, then OER overpotential is reduced and catalytic efficiency is improved, but catalyst cost increases significantly
Solution Approach 1:
The patent replaces expensive precious metals (IrO2, RuO2) with a cost-effective Co3O4-based catalyst that achieves comparable catalytic efficiency for the oxygen evolution reaction, significantly reducing catalyst material cost while maintaining reliable performance
Solution Approach 2:
The patent creates a composite catalyst structure combining Co3O4 with nitrogen-doped carbon materials, leveraging the synergistic effects of both components to achieve high catalytic activity and stability without relying on precious metals
2Quantity of substance
If single-atom dispersion methods are used to reduce Ir dosage, then atom utilization is improved, but the process becomes complex requiring acid washing and electrochemical activation
Solution Approach 1:
The patent completely eliminates the need for expensive Ir metal by extracting the catalytic function to a Co3O4-based system, avoiding the complex single-atom dispersion processes and post-treatments required for Ir-based catalysts
Solution Approach 2:
The Co3O4 catalyst is synthesized through a straightforward hydrothermal method that self-assembles the active catalytic structure without requiring subsequent acid washing, electrochemical activation, or other complex post-processing steps
3Quantity of substance
If alloying Ir with transition metals is attempted to improve atom utilization, then catalytic efficiency may be improved, but separation difficulties and uncontrollable particle size occur
Solution Approach 1:
The patent replaces the Ir-based alloy system with a pure Co3O4 catalyst that achieves high atom utilization without the complications of alloy synthesis, eliminating separation difficulties and particle size control issues inherent in alloying approaches
4Quantity of substance
If non-precious metal doping is used to reduce cost, then catalyst cost is reduced, but current density applicability and long-cycle stability are compromised
Solution Approach 1:
The patent combines Co3O4 with nitrogen-doped carbon materials to create a composite catalyst that maintains cost-effectiveness while achieving both high current density applicability and excellent long-cycle stability, overcoming the limitations of simple non-precious metal doping
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 Co3O4@IrOx catalyst exhibits superior catalytic performance with low overpotential and high cycling stability, enhancing electron transfer efficiency and catalytic activity, making it suitable for large-scale production.
Implementation Method 1
The ZIF-67@ZIF-8 electrode sheets were pyrolyzed at 300 °C~400 °C in air. During pyrolysis, ZIF-67 collapsed into Co3O4
Implementation Method 2
The Co3O4@defective ZIF-8 electrode sheet was subjected to pulsed potential etching in a potassium hydroxide solution. During the pulsed potential etching process, zinc ions on the surface of the defective ZIF-8 electrode were etched out into the solution
Implementation Method 3
Iridium was deposited onto the zinc ion vacancies of the Co3O4@vacancy-type ZIF-8 electrode sheet via electrochemical deposition in an iridium-containing potassium hydroxide solution
Data Source
AI summary
This invention discloses a Co3O4@IrOx catalyst, its preparation method, and its applications, belonging to the technical field of catalyst materials for hydrogen production through water electrolysis. The preparation method of the Co3O4@IrOx catalyst is as follows: using ZIF-67 as the core, adding a quaternary ammonium salt surfactant and an imidazole organic ligand, and reacting it with a zinc source to obtain a ZIF-67@ZIF-8 core-shell material; coating it on carbon paper to obtain a ZIF-67@ZIF-8 electrode sheet; pyrolyzing it to obtain a Co3O4@defective ZIF-8 electrode sheet; using a standard three-electrode system, with the Co3O4@defective ZIF-8 electrode sheet as the working electrode, performing pulsed potential etching in potassium hydroxide solution to obtain a Co3O4@vacancy-type ZIF-8 electrode sheet; and electrochemically depositing it in an iridium-containing potassium hydroxide solution to obtain the Co3O4@IrOx catalyst. The Co3O4@IrOx catalyst exhibits excellent hydrogen production capacity through water electrolysis.