Effect of Electronic Conductivities of Iridium Oxide/Doped SnO2 Oxygen-Evolving Catalysts on the Polarization Properties in Proton Exchange Membrane Water Electrolysis

We have developed IrOx/M-SnO2 (M = Nb, Ta, and Sb) anode catalysts, IrOx nanoparticles uniformly dispersed on M-SnO2 supports with fused-aggregate structures, which make it possible to evolve oxygen efficiently, even with a reduced amount of noble metal (Ir) in proton exchange membrane water electrolysis. Polarization properties of IrOx/M-SnO2 catalysts for the oxygen evolution reaction (OER) were examined at 80 °C in both 0.1 M HClO4 solution (half cell) and a single cell with a Nafion® membrane (thickness = 50 μm). While all catalysts exhibited similar OER activities in the half cell, the cell potential (Ecell) of the single cell was found to decrease with the increasing apparent conductivities (σapp, catalyst) of these catalysts: an Ecell of 1.61 V (voltage efficiency of 92%) at 1 A cm−2 was achieved in a single cell by the use of an IrOx/Sb-SnO2 anode (highest σapp, catalyst) with a low Ir-metal loading of 0.11 mg cm−2 and Pt supported on graphitized carbon black (Pt/GCB) as the cathode with 0.35 mg cm−2 of Pt loading. In addition to the reduction of the ohmic loss in the anode catalyst layer, the increased electronic conductivity contributed to decreasing the OER overpotential due to the effective utilization of the IrOx nanocatalysts on the M-SnO2 supports, which is an essential factor in improving the performance with low noble metal loadings.

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Earth-Abundant Electrocatalysts in Proton Exchange Membrane Electrolyzers

10.20944/preprints201811.0077.v2 ◽

2018 ◽

Author(s):

Xinwei Sun ◽

Kaiqi Xu ◽

Christian Fleischer ◽

Xin Liu ◽

Mathieu Grandcolas ◽

...

Keyword(s):

Noble Metal ◽

Proton Exchange Membrane ◽

Water Electrolysis ◽

Metal Catalysts ◽

Proton Exchange ◽

Widespread Application ◽

Noble Metal Catalysts ◽

Production Of Hydrogen ◽

Earth Abundant ◽

Exchange Membrane

Water electrolysis provides efficient and cost-effective production of hydrogen from renewable energy. Currently, the oxidation half-cell reaction relies on noble-metal catalysts, impeding widespread application. In order to adopt water electrolyzers as the main hydrogen production systems, it is critical to develop inexpensive and earth-abundant catalysts. This review discusses the proton exchange membrane (PEM) water electrolysis (WE) and the progress in replacing the noble-metal catalysts with earth-abundant ones. Researchers within this field are aiming to improve the efficiency and stability of earth-abundant catalysts (EACs), as well as to discover new ones. The latter is particularly important for the oxygen evolution reaction (OER) under acidic media, where the only stable and efficient catalysts are noble-metal oxides, such as IrOx and RuOx. On the other hand, there is significant progress on EACs for the hydrogen evolution reaction (HER) in acidic conditions, but how many of these EACs have been used in PEM WEs and tested under realistic conditions? What is the current status on the development of EACs for the OER? These are the two main questions this review addresses.

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Earth-Abundant Electrocatalysts in Proton Exchange Membrane Electrolyzers

10.20944/preprints201811.0077.v1 ◽

2018 ◽

Author(s):

Xinwei Sun ◽

Kaiqi Xu ◽

Christian Fleischer ◽

Xin Liu ◽

Mathieu Grandcolas ◽

...

Keyword(s):

Noble Metal ◽

Proton Exchange Membrane ◽

Water Electrolysis ◽

Metal Catalysts ◽

Proton Exchange ◽

Widespread Application ◽

Noble Metal Catalysts ◽

Production Of Hydrogen ◽

Earth Abundant ◽

Exchange Membrane

Water electrolysis provides efficient and cost-effective production of hydrogen from renewable energy. Currently, the oxidation half-cell reaction relies on noble-metal catalysts, impeding widespread application. In order to adopt water electrolyzers as the main hydrogen production systems, it is critical to develop inexpensive and earth-abundant catalysts. This review discusses the proton exchange membrane (PEM) water electrolysis (WE) and the progress in replacing the noble-metal catalysts with earth-abundant ones. Researchers within this field are aiming to improve the efficiency and stability of earth-abundant catalysts (EACs), as well as to discover new ones. The latter is particularly important for the oxygen evolution reaction (OER) under acidic media, where the only stable and efficient catalysts are noble-metal oxides, such as IrOx and RuOx. On the other hand, there is significant progress on EACs for the hydrogen evolution reaction (HER) in acidic conditions, but how many of these EACs have been used in PEM WEs and tested under realistic conditions? What is the current status on the development of EACs for the OER? These are the two main questions this review addresses.

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Earth-Abundant Electrocatalysts in Proton Exchange Membrane Electrolyzers

Catalysts ◽

10.3390/catal8120657 ◽

2018 ◽

Vol 8 (12) ◽

pp. 657 ◽

Cited By ~ 11

Author(s):

Xinwei Sun ◽

Kaiqi Xu ◽

Christian Fleischer ◽

Xin Liu ◽

Mathieu Grandcolas ◽

...

Keyword(s):

Noble Metal ◽

Proton Exchange Membrane ◽

Water Electrolysis ◽

Metal Catalysts ◽

Proton Exchange ◽

Noble Metal Catalysts ◽

Earth Abundant ◽

Noble Metal Oxides ◽

Acidic Conditions ◽

Exchange Membrane

In order to adopt water electrolyzers as a main hydrogen production system, it is critical to develop inexpensive and earth-abundant catalysts. Currently, both half-reactions in water splitting depend heavily on noble metal catalysts. This review discusses the proton exchange membrane (PEM) water electrolysis (WE) and the progress in replacing the noble-metal catalysts with earth-abundant ones. The efforts within this field for the discovery of efficient and stable earth-abundant catalysts (EACs) have increased exponentially the last few years. The development of EACs for the oxygen evolution reaction (OER) in acidic media is particularly important, as the only stable and efficient catalysts until now are noble-metal oxides, such as IrOx and RuOx. On the hydrogen evolution reaction (HER) side, there is significant progress on EACs under acidic conditions, but there are very few reports of these EACs employed in full PEM WE cells. These two main issues are reviewed, and we conclude with prospects for innovation in EACs for the OER in acidic environments, as well as with a critical assessment of the few full PEM WE cells assembled with EACs.

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Highly proton conductive membranes based on carboxylated cellulose nanofibres and their performance in proton exchange membrane fuel cells

10.26434/chemrxiv.7851461.v3 ◽

2019 ◽

Author(s):

Valentina Guccini ◽

Annika Carlson ◽

Shun Yu ◽

Göran Lindbergh ◽

Rakel Wreland Lindström ◽

...

Keyword(s):

Fuel Cells ◽

Fuel Cell ◽

Surface Charge ◽

Proton Exchange Membrane ◽

Membrane Surface ◽

Proton Exchange ◽

Membrane Thickness ◽

Fuel Cell Performance ◽

Cellulose Nanofibres ◽

Exchange Membrane

The performance of thin carboxylated cellulose nanofiber-based (CNF) membranes as proton exchange membranes in fuel cells has been measured in-situ as a function of CNF surface charge density (600 and 1550 µmol g-1), counterion (H+or Na+), membrane thickness and fuel cell relative humidity (RH 55 to 95 %). The structural evolution of the membranes as a function of RH as measured by Small Angle X-ray scattering shows that water channels are formed only above 75 % RH. The amount of absorbed water was shown to depend on the membrane surface charge and counter ions (Na+or H+). The high affinity of CNF for water and the high aspect ratio of the nanofibers, together with a well-defined and homogenous membrane structure, ensures a proton conductivity exceeding 1 mS cm-1at 30 °C between 65 and 95 % RH. This is two orders of magnitude larger than previously reported values for cellulose materials and only one order of magnitude lower than Nafion 212. Moreover, the CNF membranes are characterized by a lower hydrogen crossover than Nafion, despite being ≈ 30 % thinner. Thanks to their environmental compatibility and promising fuel cell performance the CNF membranes should be considered for new generation proton exchange membrane fuel cells.

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Proton exchange membrane water electrolysis: Modeling for hydrogen flow rate control

International Journal of Hydrogen Energy ◽

10.1016/j.ijhydene.2020.11.276 ◽

2021 ◽

Vol 46 (11) ◽

pp. 7676-7700

Author(s):

Rebah Maamouri ◽

Damien Guilbert ◽

Michel Zasadzinski ◽

Hugues Rafaralahy

Keyword(s):

Flow Rate ◽

Rate Control ◽

Proton Exchange Membrane ◽

Water Electrolysis ◽

Proton Exchange ◽

Hydrogen Flow Rate ◽

Hydrogen Flow ◽

Flow Rate Control ◽

Exchange Membrane

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Degradation Investigation of Electrocatalyst in Proton Exchange Membrane Fuel Cell at a High Energy Efficiency

Molecules ◽

10.3390/molecules26133932 ◽

2021 ◽

Vol 26 (13) ◽

pp. 3932

Author(s):

Jie Song ◽

Qing Ye ◽

Kun Wang ◽

Zhiyuan Guo ◽

Meiling Dou

Keyword(s):

Energy Efficiency ◽

Single Cell ◽

Proton Exchange Membrane ◽

Cell Voltage ◽

High Energy ◽

Proton Exchange ◽

Pt Catalyst ◽

Operation Conditions ◽

High Efficient ◽

Exchange Membrane

The development of high efficient stacks is critical for the wide spread application of proton exchange membrane fuel cells (PEMFCs) in transportation and stationary power plant. Currently, the favorable operation conditions of PEMFCs are with single cell voltage between 0.65 and 0.7 V, corresponding to energy efficiency lower than 57%. For the long term, PEMFCs need to be operated at higher voltage to increase the energy efficiency and thus promote the fuel economy for transportation and stationary applications. Herein, PEMFC single cell was investigated to demonstrate its capability to working with voltage and energy efficiency higher than 0.8 V and 65%, respectively. It was demonstrated that the PEMFC encountered a significant performance degradation after the 64 h operation. The cell voltage declined by more than 13% at the current density of 1000 mA cm−2, due to the electrode de-activation. The high operation potential of the cathode leads to the corrosion of carbon support and then causes the detachment of Pt nanoparticles, resulting in significant Pt agglomeration. The catalytic surface area of cathode Pt is thus reduced for oxygen reduction and the cell performance decreased. Therefore, electrochemically stable Pt catalyst is highly desirable for efficient PEMFCs operated under cell voltage higher than 0.8 V.

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On the Effect of Anion Exchange Ionomer Binders in Bipolar Electrode Membrane Interface Water Electrolysis

Journal of Materials Chemistry A ◽

10.1039/d1ta00747e ◽

2021 ◽

Author(s):

Britta Mayerhöfer ◽

Konrad Ehelebe ◽

Florian Dominik Speck ◽

Markus Bierling ◽

Johannes Bender ◽

...

Keyword(s):

Proton Exchange Membrane ◽

Water Electrolysis ◽

Membrane Electrode Assembly ◽

Proton Exchange ◽

Membrane Electrode ◽

Bipolar Electrode ◽

Electrode Interface ◽

Exchange Membrane ◽

Electrode Membrane ◽

Pem Water Electrolyzer

Bipolar membrane|electrode interface water electrolyzers (BPEMWE) were found to outperform a proton exchange membrane (PEM) water electrolyzer reference in a similar membrane electrode assembly (MEA) design based on individual porous...

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