GB/T 20042.4-2025 Proton exchange membrane fuel cell—Part 4: Test method for electrocatalysts English, Anglais, Englisch, Inglés, えいご
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ICS 27.070
CCS H 57
National Standard of the People's Republic of China
GB/T 20042.4-2025
Replaces GB/T 20042.4-2009
Proton exchange membrane fuel cell - Part 4: Test method for eleetrocatalysts
Issue date: 2025-08-29 Implementation date: 2026-03-01
Issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
the Standardization Administration of the People's Republic of China
Contents
Foreword
Introduction
1 Scope
2 Normative References
3 Terms and Definitions
4 General Safety Requirements
5 Moisture Content Test
6 Metal Element Content Test
7 Specific Surface Area and Pore Size Distribution Test
8 Morphology and Particle Size Distribution Test
9 Crystalline Structure and Average Particle Size Test
10 Bulk Density Test
11 Half-Cell Electrochemical Surface Area (ECSA) Test
12 Half-Cell Oxygen Reduction Reaction (ORR) Polarization Curve Test
13 Half-Cell ORR Catalyst Durability Test
14 Half-Cell ORR Catalyst High-Potential Durability Test
15 Metal Dissolution Rate Test
16 Half-Cell Hydrogen Oxidation Reaction (HOR) Catalyst High-Potential Durability Test
17 Half-Cell HOR Catalyst CO Tolerance Test
Appendix A (Informative) Test Preparation
Appendix B (Informative) Reference Test Methods
References
Proton exchange membrane fuel cell-Part 4: Test method for eleetrocatalysts
1 Scope
This document specifies the test methods for the physical and electrochemical properties of proton exchange membrane fuel cell (PEMFC) electrocatalysts, including moisture content, metal element content, specific surface area and pore size distribution, morphology and particle size distribution, crystalline structure, bulk density, and other physical properties, as well as electrochemical active surface area (ECSA), oxygen reduction reaction (ORR) activity, durability, metal dissolution rate, and carbon monoxide (CO) tolerance.
This document is applicable to platinum-based (Pt-based) electrocatalysts for hydrogen-fueled PEMFCs. Other types of PEMFCs may also refer to this document.
2 Normative References
The following documents contain provisions that, through reference in this text, constitute essential requirements of this document. For dated references, only the edition cited applies. For undated references, the latest version (including any amendments) applies.
GB/T 5816—1995 Methods for the Determination of Surface Area of Catalysts and Adsorbents
GB/T 15072.7—2008 Methods for Chemical Analysis of Precious Metal Alloys – Determination of Chromium and Iron in Gold Alloys – Inductively Coupled Plasma Atomic Emission Spectrometry
GB/T 20042.1—2017 Proton Exchange Membrane Fuel Cells – Part 1: Terminology
GB/T 21354—2008 General Method for the Determination of Tapped Density of Powder Products
3 Terms and Definitions
Terms and definitions defined in GB/T 20042.1—2017 and the following apply to this document.
3.1 Moisture Content
The mass fraction of water contained in the electrocatalyst.
3.2 Electrochemical Active Surface Area (ECSA)
The effective electrochemically active surface area per unit mass of platinum (Pt) or total platinum group metals (PGMs) measured by electrochemical methods.
Note: The unit of ECSA is square meters per gram (m²/g).
3.3 Half-Cell
A system consisting of an electrode and its closely associated electrolyte solution.
3.4 Working Electrode (WE)
The electrode where the electrochemical reaction under study occurs during testing.
3.5 Counter Electrode (CE)
The electrode that completes the circuit with the working electrode.
3.6 Reference Electrode (RE)
An electrode used to measure the potential of the working electrode, which approaches ideal non-polarization behavior.
3.7 Three-Electrode System
A testing system consisting of a working electrode, counter electrode, reference electrode, and electrolyte solution.
3.8 Mass Activity (MA)
The absolute kinetic current per unit mass of platinum (Pt) or total platinum group metals (PGMs) at a potential of 0.9 V vs. RHE.
Note: The unit of mass activity is amperes per milligram (A/mg).
3.9 Area-Specific Activity (SA)
The kinetic current delivered per unit electrochemical active surface area of the electrocatalyst at a potential of 0.9 V vs. RHE.
Note: The unit of area-specific activity is milliamperes per square centimeter (mA/cm²).
3.10 Durability
The ability of an electrocatalyst and its support to maintain stable long-term operation under normal usage conditions.
4 General Safety Requirements
4.1 During electrocatalyst testing, oxidizing gases (e.g., O₂) and reducing gases (e.g., H₂) are typically used, which are usually stored in high-pressure containers.
Note: For hydrogen-related requirements, see GB 4962—2008.
4.2 The fuel cell itself should be capable of operating under pressurized or atmospheric conditions.
4.3 Test personnel should receive technical training, have experience operating relevant testing equipment, and be familiar with applicable safety procedures. Test preparation guidelines are provided in Appendix A.
5 Moisture Content Test
5.1 Test Equipment
Thermogravimetric analyzer (TGA).
5.2 Sample Preparation
Approximately 20 mg ± 1 mg of electrocatalyst sample should be weighed quickly and sealed for each test. The total mass should meet the requirements for three valid tests.
5.3 Test Procedure
Accurately weigh and record the initial mass (m₀) of the sample.
Transfer the sample quickly into a dried, covered crucible with perforations in the TGA.
Use an inert gas as the carrier gas at a flow rate of 50 mL/min.
Programmatically heat the sample from room temperature to 100°C at a rate of 2–10°C/min (preferably 5°C/min).
After reaching constant weight, accurately weigh and record the final mass (m₁).
Note: Constant weight is typically achieved when the weight change rate is ≤ 0.1–0.5%/min for 10 minutes.
