scholarly journals On the limitations in assessing stability of oxygen evolution catalysts using aqueous model electrochemical cells

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Julius Knöppel ◽  
Maximilian Möckl ◽  
Daniel Escalera-López ◽  
Kevin Stojanovski ◽  
Markus Bierling ◽  
...  
Keyword(s):  
Oxygen Evolution ◽  
Inductively Coupled Plasma ◽  
Catalyst Layer ◽  
Operating Conditions ◽  
Model Systems ◽  
Membrane Electrode ◽  
Inductively Coupled ◽  
System A ◽  
Membrane Electrode Assemblies ◽  
Electrode Assemblies

AbstractRecent research indicates a severe discrepancy between oxygen evolution reaction catalysts dissolution in aqueous model systems and membrane electrode assemblies. This questions the relevance of the widespread aqueous testing for real world application. In this study, we aim to determine the processes responsible for the dissolution discrepancy. Experimental parameters known to diverge in both systems are individually tested for their influence on dissolution of an Ir-based catalyst. Ir dissolution is studied in an aqueous model system, a scanning flow cell coupled to an inductively coupled plasma mass spectrometer. Real dissolution rates of the Ir OER catalyst in membrane electrode assemblies are measured with a specifically developed, dedicated setup. Overestimated acidity in the anode catalyst layer and stabilization over time in real devices are proposed as main contributors to the dissolution discrepancy. The results shown here lead to clear guidelines for anode electrocatalyst testing parameters to resemble realistic electrolyzer operating conditions.

scholarly journals On the limitations in assessing stability of oxygen evolution catalysts using aqueous model electrochemical cells

2020 ◽  
Author(s):  
Julius Knöppel ◽  
Maximilian Möckl ◽  
Daniel Escalera-López ◽  
Kevin Stojanovski ◽  
Markus Bierling ◽  
...  
Keyword(s):  
Oxygen Evolution ◽  
Inductively Coupled Plasma ◽  
Catalyst Layer ◽  
Operating Conditions ◽  
Model Systems ◽  
Membrane Electrode ◽  
Inductively Coupled ◽  
System A ◽  
Real World Application ◽  
Electrode Assemblies

Abstract Recent research indicates a severe discrepancy between oxygen evolution reaction (OER) catalysts dissolution in aqueous model systems and membrane electrode assemblies (MEA). This questions the relevance of the widespread aqueous testing for real world application. In this study, we aim to determine the processes responsible for the dissolution discrepancy. Experimental parameters known to diverge in both systems are individually tested for their influence on dissolution of an Ir-based catalyst. Ir dissolution is studied in an aqueous model system, a scanning flow cell coupled to an inductively coupled plasma mass spectrometer. Real dissolution rates of the Ir OER catalyst in MEA are measured with a specifically developed, dedicated setup. Overestimated acidity in the anode catalyst layer and stabilization over time in MEAs are identified as main contributors to the dissolution discrepancy. The results shown here lead to clear guidelines for OER electrocatalyst testing parameters to resemble realistic PEMWE operating conditions.

Development of Production Technology for Membrane-Electrode Assemblies With Radical Capturing Layer

2013 ◽  
Vol 10 (1) ◽  
Author(s):  
Toshiro Kobayashi ◽  
Etsuro Hirai ◽  
Hideki Itou ◽  
Takuya Moriga
Keyword(s):  
Production Technology ◽  
Mass Production ◽  
Catalyst Layer ◽  
Gas Diffusion ◽  
Membrane Electrode ◽  
Continuous Formation ◽  
Forming Technology ◽  
Membrane Electrode Assemblies ◽  
Electrode Assemblies ◽  
Opening Ratio

This paper describes the development of mass-production technology for membrane-electrode assemblies (MEA) with a radical capturing layer and verifies its performance. Some of the authors of this paper previously developed an MEA with a radical capturing layer along the boundaries between the electrode catalyst layer and the polymer membrane to realize an endurance time of 20,000 h in accelerated daily start and daily stop (DSS) deterioration tests. Commercialization of these MEAs requires a production technology that suits mass production lines and provides reasonable cost performance. After developing a water-based slurry and selecting a gas diffusion layer (GDL), a catalyst layer forming technology uses a rotary screen method for electrode formation. Studies confirmed continuous formation of the catalyst layer, obtaining an anode/cathode thickness of 55 μm (+10/−20)/50 μm (+10/−20) by optimizing the opening ratio and thickness of the screen plate. A layer-forming technology developed for the radical capturing layer uses a two-fluid spraying method. Continuous formation of an 8 μm thick (±3 μm) radical capturing layer proved feasible by determining the appropriate slurry viscosity, spray head selection, and optimization of spraying conditions.

scholarly journals (M,Ru)O2 (M = Mg, Zn, Cu, Ni, Co) Rutiles and Their Use as Oxygen Evolution Electrocatalysts in Membrane Electrode Assemblies under Acidic Conditions

2020 ◽  
Vol 32 (14) ◽  
pp. 6150-6160
Author(s):  
David L. Burnett ◽  
Enrico Petrucco ◽  
Katie M. Rigg ◽  
Christopher M. Zalitis ◽  
Jamie G. Lok ◽  
...  
Keyword(s):  
Oxygen Evolution ◽  
Membrane Electrode ◽  
Membrane Electrode Assemblies ◽  
Electrode Assemblies ◽  
Acidic Conditions

Development of Production Technology for Membrane-Electrode Assemblies With Radical Capturing Layer

2011 ◽  
Author(s):  
T. Kobayashi ◽  
E. Hirai ◽  
H. Itoh ◽  
T. Moriga
Keyword(s):  
Production Technology ◽  
Mass Production ◽  
Catalyst Layer ◽  
Gas Diffusion ◽  
Membrane Electrode ◽  
Continuous Formation ◽  
Forming Technology ◽  
Membrane Electrode Assemblies ◽  
Electrode Assemblies ◽  
Opening Ratio

This paper describes the development of mass-production technology for membrane-electrode assemblies (MEA) with a radical capturing layer and verifies its performance. Some of the authors of this paper previously developed an MEA with a radical capturing layer along the boundaries between the electrode catalyst layer and the polymer membrane to realize an endurance time of 20,000 h in accelerated daily start and daily stop (DSS) deterioration tests. Commercialization of these MEAs requires a production technology that suits mass production lines and provides reasonable cost performance. After developing a water-based slurry and selecting a gas diffusion layer (GDL), a catalyst layer forming technology uses a rotary screen method for electrode formation. Studies confirmed continuous formation of the catalyst layer, obtaining an anode/cathode thickness of 55 μm (+10/−20)/50 μm (+10/−20) by optimizing the opening ratio and thickness of the screen plate. A layer-forming technology developed for the radical capturing layer uses a two-fluid spraying method. Continuous formation of an 8-μm-thick (±3 μm) radical capturing layer proved feasible by determining the appropriate slurry viscosity, spray head selection, and optimization of spraying conditions.

scholarly journals Local degradation effects in automotive size membrane electrode assemblies under realistic operating conditions

2020 ◽  
Vol 260 ◽  
pp. 114291 ◽  
Author(s):  
Tim Lochner ◽  
Laurens Hallitzky ◽  
Markus Perchthaler ◽  
Michael Obermaier ◽  
Jarek Sabawa ◽  
...  
Keyword(s):  
Operating Conditions ◽  
Membrane Electrode ◽  
Membrane Electrode Assemblies ◽  
Electrode Assemblies

Modeling Ultrasonic Sealing of Membrane Electrode Assemblies for High-Temperature PEM Fuel Cells

2011 ◽  
Author(s):  
Dave C. Guglielmo ◽  
Todd T. B. Snelson ◽  
Daniel F. Walczyk
Keyword(s):  
Fuel Cells ◽  
High Temperature ◽  
Catalyst Layer ◽  
Pem Fuel Cells ◽  
Membrane Electrode ◽  
Ultrasonic Bonding ◽  
Membrane Electrode Assemblies ◽  
Electrode Assemblies ◽  
Physics Simulation ◽  
High Temperature Pem

Ultrasonic bonding, with its extremely fast cycle times and energy efficiency, is being investigated as an important manufacturing technology for future mass production of fuel cells. The objectives of the authors’ research are to (1) create a multi-physics simulation model that predicts through-thickness energy distribution and temperature gradients during ultrasonic sealing of polybenzimidazole (PBI) based Membrane Electrode Assemblies (MEAs) for High Temperature PEM fuel cells, and (2) correlate the model with experimentally measured internal interface (e.g., membrane/catalyst layer) temperatures. The multi-physics model incorporates the electrode and membrane material properties (stiffness and damping) in conjunction with the ultrasonic process parameters including pressure, energy flux and vibration amplitude. Overall, the processing of MEAs with ultrasonic bonding rather than a hydraulic thermal press results in MEAs that meet or exceed required performance specifications, and potentially reduces the manufacturing time from minutes to seconds.

Mathematical Modeling of a DMFC Cathode with a Double Catalyst Layered Structure Membrane Electrode Assemblies

2013 ◽  
Vol 690-693 ◽  
pp. 989-992
Author(s):  
Chun Guang Suo ◽  
Wen Bin Zhang ◽  
Da Da Wang
Keyword(s):  
Catalyst Layer ◽  
Membrane Electrode ◽  
Fabrication Technology ◽  
Cathode Electrode ◽  
Membrane Electrode Assemblies ◽  
Electrode Assemblies ◽  
Direct Methanol ◽  
Semi Empirical ◽  
Mass Transport Coefficient ◽  
Methanol Fuel Cell

Membrane electrode assemblies (MEA) is the key component of a direct methanol fuel cell (DMFC) and its structure and fabrication technology influenced the performance of DMFC a lot. A novel structured MEA including a hydrophilic inner thin catalyst layer and a traditional outer catalyst layer, provide higher performance. To optimize the combination of the two catalysts layer a mathematical model based on Tafel type kinetics and semi-empirical mass transport coefficient was applied. The simulation of cathode overpotential results showed a DMFC with a 5μm thick inner Pt Blk catalyst layer and an 8μm thick outer 40wt%Pt/C catalyst layer as cathode electrode was the best.

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