Exchange Membrane Fuel Cell Anode Research Articles

Multi-response optimization of ejector for proton exchange membrane fuel cell anode systems by the response surface methodology and desirability function approach

ABSTRACT In a fuel cell system, the performance of the ejector is limited when it operates under off-design conditions. To improve the performance of the ejector under all operating conditions in the fuel cell system, this study employs a multi-response optimization approach to optimize the structural parameters of the ejector. The optimization objectives are the entrainment ratio under low-power and high-power operating conditions, with the optimization variables including the mixing tube diameter (D m ), primary nozzle exit position (L nxp ), and mixing tube length (L m ). A quadratic polynomial model is proposed to correlate the key structural parameters of the ejector with the entrainment ratio using the response surface methodology based on the Box-Behnken design. The optimal structural parameters of the ejector are obtained using the desirability function approach. The results demonstrate that this optimization approach significantly improves the ejector performance under off-design conditions while the performance remains essentially unchanged under high-power operating conditions.

High CO and sulfur tolerant proton exchange membrane fuel cell anodes enabled by “work along both lines” mechanism of 2,6-dihydroxymethyl pyridine molecule blocking layer

Proton exchange membrane fuel cells (PEMFCs) are hindered by their poor tolerance to CO and H2S poisoning. Herein, we report an effective method, via engineering 2,6-dihydroxymethyl pyridine (DhmPy) molecule blocking layers on Pt surface, aiming to save the poisoning issue for PEMFC anode reaction. The PEMFCs assembled by this catalyst produce a power density of 1.18 W cm−2 @ 2.0 A cm−2 and 1.32 W cm−2 @ 2.0 A cm−2, far exceeding commercial Pt/C after H2/10 ppm CO poisoning and H2/5 ppm H2S poisoning tests, respectively. Density functional theory (DFT) indicates that a coronal molecule layer with a steric confinement height (1.82 Å), constructed by DhmPy, emerges more intensive adsorption energy compared to 2,6-pyridinedicarboxamide (DcaPy) and 2,6-diacetylpyridine (DAcPy), thereby more effectively inhibits the adsorption of large-sized CO and H2S on Pt surface without affecting H2 traverse. This “work along both lines” mechanism with the resistance of both CO and H2S provides a new and promising design thought for high CO and sulfur tolerant PEMFC anodes.

(Digital Presentation) Investigation of Reversal Tolerant Anode Catalysts Ageing during Start-up/Shut-Down Events on a PEM Fuel Cell

Durability of automotive polymer electrolyte membrane fuel cells (PEMFC) strongly depends on transient operating conditions such as start-up/shut-down (SUSD). During SUSD events, the hydrogen atmosphere at the anode compartment can be replaced by air (shut-down) and vice-versa (start-up), which can lead to the formation of a hydrogen and air interface in the anode side resulting in a lack of hydrogen supply situation. In the event of a hydrogen-starved situation, the carbon-based support material can be oxidized to supply the necessary electron to complete the load circuit resulting in cell reversal mode, when the anode potential rises above 1.0 V (vs. reversible hydrogen electrode). Such events can damage the anode catalyst layer and reduce the fuel cell lifetime. One of the many ways to mitigate the cell reversal condition is to incorporate reversal tolerant anode catalysts with hydrogen oxidation reaction (HOR) catalysts to facilitate the oxygen evolution reaction (OER) over the carbon oxidation reaction (COR) 1.IrO2 is commonly used as a reversal tolerant anode catalyst because of its high activity and stability under acidic conditions. Several studies have shown the effectiveness of IrO2 as an OER catalyst to alleviate cell reversal events 2. Recent studies have shown that IrO2 can be reduced to metallic Ir under highly reducing hydrogen atmosphere in PEM fuel cell anodes 3. While IrO2 serves its purpose as an OER catalyst, the stability of IrO2 under the transient operation of a PEM fuel cell, such as SUSD, and the impact on overall catalyst durability as well as cell performance are still unresolved.In this work, we have developed an accelerated stress test (AST) which allows to simulate the transient operation during SUSD analogous to real operation of a PEM fuel cell by an active gas switch from hydrogen to air at the anode side. We discuss the consequences of this transient SUSD condition on the anode catalyst as well as cathode catalyst layer characterized by cyclic voltammetry, where hydrogen under potential deposition (Hupd) features show the change in effective catalyst surface area. The impact on reversal tolerance performance of the IrO2 OER catalyst has been determined by the extended exposure to reversal conditions. Post-characterization surface analysis by X-ray photoelectron spectroscopy (XPS) reveals the change of chemical state of the materials on both anode and cathode catalyst layers resulting from active gas switching at the anode. Finally, the overall PEM fuel cell performance and durability are discussed. References Hong, B. K., Mandal, P., Oh, J.-G. & Litster, S. On the impact of water activity on reversal tolerant fuel cell anode performance and durability. Journal of Power Sources 328, 280–288 (2016).Moore, C. E., Eastcott, J., Cimenti, M., Kremliakova, N. & Gyenge, E. L. Novel methodology for ex situ characterization of iridium oxide catalysts in voltage reversal tolerant proton exchange membrane fuel cell anodes. Journal of Power Sources 417, 53–60 (2019).Fathi Tovini, M. et al. Degradation Mechanism of an IrO2 Anode Co-Catalyst for Cell Voltage Reversal Mitigation under Transient Operation Conditions of a PEM Fuel Cell. J. Electrochem. Soc. 168, 064521 (2021).

New approach by electrospray technique to prepare a gas diffusion layer for the proton exchange membrane fuel cell anode

The performance of the electrospray technique was applied to obtain a gas diffusion layer (GDL) for a proton exchange membrane fuel cell. It was confirmed by confocal microscopy that polytetrafluorethylene (PTFE) was impregnated into the backbone, forming a dispersed layer of microscopic size homogeneously distributed over the substrate. The PTFE layer was characterized by infrared spectroscopy and thermogravimetric analysis. In this work, we demonstrated that the use of the GDL prepared by electrospray increases the maximum power of the H2/O2 fuel cell by about 10% and decreases the diffusion loss of the electrode owing to a better distribution characteristic hydrophobic coating with low impedance to gas diffusion. Thus, our method is promising for the development of fuel cells by the production of diffusion layers.

Numerical studies on ejector structure optimization and performance prediction based on a novel pressure drop model for proton exchange membrane fuel cell anode

The performance of hydrogen ejectors can be affected by the working conditions of the fuel cell system especially associating with the working pressure and pressure drop of the anode. However, the pressure drop characteristics model of the anode is correlated to the fuel cell parameters. In this work, a porous jump boundary is used as a pressure drop characteristics model of the anode which is weakly relevant to the parameters of fuel cells by employing the pressure drop characteristic curve of fuel cells. Based on the model, the influence of the condition parameters on the property of the ejector can be predicted. According to our results, the entrainment performance of the ejector can be influenced by anode inlet temperature, relative humidity, and differential pressure. Also, it is helpful for the design and prediction of the ejector in different fuel cell systems depend on the pressure drop.

Study of relative humidity on durability of the reversal tolerant proton exchange membrane fuel cell anode using a segmented cell

Cell voltage reversal resulted from hydrogen starvation at the anode is one of the factors that exacerbate the overall degradation of proton exchange membrane fuel cells (PEMFCs). An effective mitigation strategy is to involve oxygen evolution reaction (OER) catalysts into the anode to facilitate water electrolysis against carbon corrosion. As such, this paper aims to study the influence of relative humidity (RH) on the performance and durability of reversal-tolerant-anodes (RTAs) during hydrogen starvation. An advanced segmented technique is employed to examine the coupling reactions by simultaneously measuring current density, RH and temperature in a fuel cell with a large active area. It is found that the inlet of RTAs undergoes degradation earlier than the outlet and the membrane electrode assembly (MEA) with a RTA has an optimal humidity during cell reversal. Results also show that the failure of the RTA MEA is due to a loss of electron conduction medium rather than the deactivation of the OER catalyst. In addition, this work highlights the importance of plate flow field design and the OER catalyst gradient design of the RTA MEA.

Novel methodology for ex situ characterization of iridium oxide catalysts in voltage reversal tolerant proton exchange membrane fuel cell anodes

Fuel cell durability with respect to voltage reversal events occurring during start-up/shut-down cycles is of vital importance for stack lifetime in automotive applications. The goal of this work is to describe the activity and durability of oxygen evolution reaction (OER) catalysts in a representative proton exchange membrane fuel cell (PEMFC) anode environment. Three unsupported and one TiO2 supported IrOx OER catalysts are investigated using ex situ accelerated stress testing (AST). The catalysts are ranked based on the ex situ OER activities and the concentration of dissolved Ir in the electrolyte after ex situ AST. Furthermore, the ex situ interaction between IrOx and the hydrogen oxidation reaction (HOR) catalyst Pt/C is investigated to better understand the voltage reversal performance in fuel cells. The ex situ results are compared with reversal times and reversal time losses (i.e., difference between beginning of test (BOT) and end of test (EOT) reversal times) obtained in a PEMFC subjected to accelerated anode stress test (AAST). Generally, catalysts with higher ex situ OER mass activity and Ir dissolution produced the longest BOT reversal times. The smallest reversal loss (i.e., highest OER durability) is shown by IrOx/TiO2. Regarding unsupported IrOx, heat treatment increasing crystallinity is an effective method to increase OER durability in the fuel cell anode environment.

Polylaminate TaN/Ta coating modified ferritic stainless steel bipolar plate for high temperature proton exchange membrane fuel cell

A polylaminate coating with intersecting tantalum and tantalum nitride (TaN/Ta/TaN/Ta/TaN/Ta, TaN is the outermost layer) is deposited on surface of 430 stainless steel bipolar plate for high temperature proton exchange membrane fuel cell by a reactive magnetron sputtering method. Electrochemical tests including potentiodynamic, potentiostatic polarisation and electrochemical impedance spectroscopy, are carried out to evaluate the corrosion resistance and stability of the polylaminate TaN/Ta coating in simulating high temperature proton exchange membrane fuel cell environments (85% H3PO4 solution at 80 °C and 130 °C). Results show that the polylaminate TaN/Ta coating greatly improve the corrosion resistance of 430 stainless steel, which can provide almost 100% protection of the substrate in both high temperature proton exchange membrane fuel cell anode and cathode environment. Besides, the interfacial contact resistance of coated 430 stainless steel (9.03 mΩ cm2) is much lower than that of bare substrate (106.74 mΩ cm2). Furthermore, different from the highly increased interfacial contact resistance of bare specimen, the coated 430 stainless steel shows a minor increase resistance after potentiostatic tests in 85% H3PO4 solution at 130 °C.

Activity and Stability of Dispersed Multi Metallic Pt-based Catalysts for CO Tolerance in Proton Exchange Membrane Fuel Cell Anodes.

Studies aiming at improving the activity and stability of dispersed W and Mo containing Pt catalysts for the CO tolerance in proton exchange membrane fuel cell (PEMFC) anodes are revised for the following catalyst systems: (1) a carbon supported PtMo electrocatalyst submitted to heat treatments; (2) Pt and PtMo nanoparticles deposited on carbon-supported molybdenum carbides (Mo2C/C); (3) ternary and quaternary materials formed by PtMoFe/C, PtMoRu/C and PtMoRuFe/C and; (4) Pt nanoparticles supported on tungsten carbide/carbon catalysts and its parallel evaluation with carbon supported PtW catalyst. The heat-treated (600 oC) Pt-Mo/C catalyst showed higher hydrogen oxidation activity in the absence and in the presence of CO and better stability, compared to all other Mo-containing catalysts. PtMoRuFe, PtMoFe, PtMoRu supported on carbon and Pt supported on Mo2C/C exhibited similar CO tolerances but better stability, as compared to as-prepared PtMo supported on carbon. Among the tungsten-based catalysts, tungsten carbide supported Pt catalyst showed reasonable performance and reliable stability in comparison to simple carbon supported PtW catalyst, though an uneven level of catalytic activity towards H2 oxidation in presence of CO is observed for the former as compared to Mo containing catalyst. However, a small dissolution of Mo, Ru, Fe and W from the anodes and their migration toward cathodes during the cell operation is observed. These results indicate that the fuel cell performance and stability has been improved but not yet totally resolved.

(Invited) Plasma Assisted Preparation of Low Pt Content Proton Exchange Membrane Fuel Cell Anode Catalysts

Pt doped cerium oxide thin films with a nano-porous structure was prepared by reactive rf magnetron deposition on a fuel cell gas diffusion layer (GDL) coated with nitrogenated amorphous carbon films (CNx) as an interlayer. We show that the structure and morphology of the cerium oxide-CNx composites depend on the oxygen and nitrogen concentration in working gas used for catalyst deposition. Considerable plasma erosion of the carbonaceous interlayer accompanied by the formation of highly porous carbon/cerium oxide bilayer systems is reported. Oxygen plasma etching of the carbon interlayer occurring simultaneously with cerium oxide film growth is considered to be the driving force for the formation of cerium oxide film nanoporosity with large active surface. Thin film techniques permits to grow the catalyst film characterized by highly dispersed platinum showing high hydrogen oxidation activity and stability. These new materials may help to substantially reduce the demand for expensive noble-metals in proton exchange membrane fuel cell (PEMFC) catalytic applications. We measured Pt-CeOx thin film anode catalyst activity in hydrogen PEMFC and compared it with performance of a standard reference cell. We showed that membrane electrode assembly (MEA) made by assembling Pt-CeOx/CNx anode, containing 2-4 μg per cm2 only, and a reference standard cathode can deliver 1.2 W/cm2 power density.

Activity and Stability of Molybdenum-Containing Dispersed Pt Catalysts for CO Tolerance in Proton Exchange Membrane Fuel Cell Anodes

In this work, results of attempts to improve the activity and stability of Mo-containing dispersed Pt catalysts for the CO tolerance in proton exchange membrane fuel cell (PEMFC) anodes are revised for the following approaches: (1) application of a heat treatment at various temperatures ranging from 400 to 700 °C on carbon supported PtMo (60:40, Pt:Mo) electrocatalyst; (2) deposition of Pt and PtMo nanoparticles on carbon-supported molybdenum carbides (Mo2C/C) and; (3) employing ternary and quaternary materials formed by PtMoFe/C, PtMoRu/C and PtMoRuFe/C. The Pt-Mo/C catalyst heat-treated at 600 °C showed higher hydrogen oxidation activity in the absence and in the presence of CO and better stability, compared to all other Mo-containing catalysts. Similar CO tolerances were observed for PtMoRuFe, PtMoFe, PtMoRu supported on carbon, and for Pt supported on Mo2C/C, which also presented better stability, as compared to as-prepared PtMo supported on carbon. However, partial dissolution of Mo, Ru, and Fe from the anodes and their migration toward cathodes during the cell operation was observed.

Activity and Stability of Molybdenum-Containing Dispersed Pt Catalysts for CO Tolerance in Proton Exchange Membrane Fuel Cell Anodes

Previous work conducted on carbon supported bimetallic (Pt-M/C, where M = Sn, Fe, Co, W or Mo, etc) catalysts have demonstrated the considerable CO tolerance of these materials when reformate hydrogen gas is used to feed the proton exchange membrane fuel cell (PEMFC) anodes. Among these bimetallic electrocatalysts, Pt-Mo composites have shown the most promising CO tolerance. This includes carbon supported Pt-Mo nanoparticles and various Pt electrodes whose surface was modified either with Mo oxides or some other Mo species. While a good CO tolerance of the anode electrocatalysts is a key challenge in the low temperature fuel cell technology, a high level of catalyst stability is also required to tolerate dynamic operating conditions involved in practical applications. Studies have shown that carbon supported Pt-Mo electrocatalysts present a CO tolerance up to threefold the tolerance of the state-of-the-art Pt-Ru/C catalysts, but their long term stability regarding the CO poisoning is under open discussion. This work reviews attempts to improve the activity and stability of Mo-containing dispersed Pt catalysts for CO tolerance in PEMFC anodes, made by using the following approaches: (1) application of a heat treatment at various temperatures ranging from 400 to 700 °C on carbon supported Pt-Mo (60:40, Pt:Mo) electrocatalyst; (2) deposition of Pt and Pt-Mo nanoparticles on carbon-supported molybdenum carbides and oxides (Mo2C/C, MoOx/C) prepared by different methods, and; (3) employing ternary and quaternary materials formed by Pt-Mo-Fe/C, Pt-Mo-Ru/C and Pt-Mo-Ru-Fe/C. Depositions of the metallic particles on the different substrates were made by a formic acid reduction process. Catalyst samples were characterized by temperature programmed reduction (TPR), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Transmission electron microscopy (TEM), X-ray absorption spectroscopy (XAS), scanning electron microscopy (SEM) and wavelength dispersive X-ray spectroscopy (WDS). Electrochemical characterizations were carried out by single cell polarization measurements, CO stripping, cyclic voltammetry (CV), and online mass spectrometry (OLMS). CV and OLMS experiments have been performed to evaluate the stability and CO tolerance of the electrocatalysts. The Pt-Mo/C catalyst treated at 600 °C, for which the average crystallite size was 16.7 nm, showed a better stability up to 5000 potential cycles of cyclic voltammetry and a higher hydrogen oxidation activity in the presence of CO, compared to untreated Pt-Mo/C, giving an overpotential induced by CO contamination of 100 mV at 1 Acm-2. Similar observations were made for the PtMoRuFe/C, PtMoFe/C and PtMoRu/C electrocatalysts. In the cases of Pt and Pt-Mo supported on Mo2C/C, and also for PtMoRuFe/C, PtMoFe/C and PtMoRu/C the results also evidenced a better stability than Pt-Mo supported on carbon. In all cases, a partial dissolution of Mo from the anode and its migration toward cathode during the cell operation was observed. This was also seen for Ru and Fe, in the cases of ternary and quaternary materials. On the basis of polarization measurements and cyclic voltammograms, it is concluded that the stability of anode electrocatalysts can be improved either by heat treatment of Pt-Mo/C, or by using molybdenum carbide as catalyst support or even by using Mo-containing ternary and quaternary electrocatalysts. Acknowledgments: This work has been supported by Fundação de Amparo a Pesquisa do Estado de São Paulo and Conselho Nacional de Desenvolvimento Científico e Tecnológico, Brazil.

WO3based solid solution oxide – promising proton exchange membrane fuel cell anode electro-catalyst

Nanostructured (W1-xIrx)Oy(x= 0.3) electro-catalyst exhibits excellent electrochemical activity and stability similar to that of Pt/C, which is in agreement with the results of the theoretical first principles studies.

Molybdenum carbide-based electrocatalysts for CO tolerance in proton exchange membrane fuel cell anodes

The activity, stability and CO tolerance of molybdenum carbide-based electrocatalyts were studied in anodes of proton exchange membrane fuel cells (PEMFCs). To this purpose, carbon-supported molybdenum carbide (Mo2C/C) was prepared by an ultrasonic method, and was used as catalyst support in the anode of a PEMFC. Pt and PtMo nanoparticles were deposited on this Mo2C/C by the formic acid reduction method. The physical properties of the resulting electrocatalysts were studied by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), X-ray absorption near edge structure (XANES), scanning electron microscopy (SEM) and wavelength dispersive spectroscopy (WDS). Electrochemical characterizations were carried out by single cell polarization measurements, CO stripping, cyclic voltammetry (CV) and online mass spectrometry (OLMS). CV and OLMS experiments were performed to evaluate the stability and CO tolerance of the electrocatalysts. The results obtained for the carbide-based electrocatalysts were compared with those obtained for carbon-supported PtMo and Pt electrocatalysts. It was observed that Pt and PtMo supported on Mo2C/C present a better stability than PtMo supported on carbon. CV and WDS results evidenced a partial dissolution of Mo from the anode and its migration toward cathode during the cell operation. On the basis of polarization measurements and cyclic voltammograms, it was concluded that the stability of anode electrocatalysts can be improved by the use of molybdenum carbide as catalyst support.

Water management in alkaline anion exchange membrane fuel cell anode

Abstract Water management is an important issue for alkaline anion exchange membrane fuel cell (AAEMFC) due to its significant role in the energy conversion processes. In this study, a numerical model is developed to investigate the water transport in AAEMFC anode. The gas and liquid transport characteristics in the gas diffusion layer (GDL) and catalyst layer (CL) with different designs and under various operating conditions are discussed. The results show that the current density affects the liquid water distribution in anode most significantly, and the temperature is the second considerable factor. The stoichiometry ratio of the supplied reactant has insignificant effect on the liquid water transport in anode. The change of liquid water amount in anode with cathode relative humidity follows a similar trend with anode inlet relative humidity. Some numerical results are also explained with published experimental and modeling data with reasonable agreement.

PEM Fuel Cell Modeling and Pressure Investigation

For investigation of a proton exchange membrane fuel cell anode and cathode pressure effect on cell performance, a quasi two-dimensional, isothermal model is developed. The main solution domain is divided into two individual regions (channel and proton exchange membrane), subsequently by using two-one-dimensional models; each of these regions is modeled. The method is based on analytical methods combined with numerical techniques. For validation of modeling, an experimental setup was developed. Comparing the results with the experimental set-up has shown good agreement and acceptable accuracy of the method. Analytical results revealed that 5 bar pressure for anode and cathode sides have the best proton exchange membrane fuel cells performance.

Temperature-dependent CO desorption kinetics on supported gold nanoparticles: Relevance to clean hydrogen production and fuel cell systems

The influence of the temperature on the CO desorption process was studied on supported gold nanoparticles using isotopic exchange experiments and mass spectrometric detection. CO desorption kinetics data were measured for a range of temperature from 25 to 150 °C and for a fixed CO concentration of 1000 ppm. The measured temperature-dependent kinetics data were discussed with relation to the CO tolerance issue at the proton exchange membrane fuel cell anode, the water–gas-shift and preferential CO oxidation reactions. The high measured rates of CO desorption give support to the argument that the rate of CO adsorption/desorption (and not CO electrooxidation) plays the most significant role in determining the equilibrium CO coverage at the fuel cell anode and the subsequent CO tolerance. The measured desorption rate constants are believed to be also of added value for the development of elementary reaction step-based kinetics models for the water–gas-shift and preferential CO oxidation reactions. In addition, Arrhenius parameters were calculated and their variations provided insight into the underlying adsorption/desorption processes. The influence of a temperature cycle up to 150 °C on the properties of the supported gold nanoparticles was also assessed with regard to CO desorption kinetics and catalyst nanostructure.

A novel proton exchange membrane fuel cell anode for enhancing CO tolerance

A novel proton exchange membrane fuel cell (PEMFC) anode which can facilitate the CO oxidation by air bleeding and reduce the direct combustion of hydrogen with oxygen within the electrode is described. This novel anode consists of placing Pt or Au particles in the diffusion layer which is called Pt- or Au-refined diffusion layer. Thus, the chemical oxidation of CO occurs at Pt or Au particles before it reaches the electrochemical catalyst layer when trace amount of oxygen is injected into the anode. All membrane electrode assemblies (MEAs) composed of Pt- or Au-refined diffusion layer do perform better than the traditionary MEA when 100 ppm CO/H 2 and 2% air are fed and have the performance as excellent as the traditionary MEA with neat hydrogen. Furthermore, CO tolerance of the MEAs composed of Au-refined diffusion layer was also assessed without oxygen injection. When 100 ppm CO/H 2 is fed, MEAs composed of Au-refined diffusion layer have the slightly better performance than traditionary MEA do because Au particles in the diffusion layer have activity in the water gas shift (WGS) reaction at low temperature.

The influence of hydrogen sulfide on proton exchange membrane fuel cell anodes

The effect of hydrogen sulfide on proton exchange membrane fuel cell (PEMFC) anodes was studied by cyclic voltammetry (CV), potential steps and electrochemical impedance spectroscopy (EIS). The severity of the effect of H 2S varies depending on the H 2S concentration, current density and the cell temperature. The anode humidification does not impact the poisoning rate much when the anode is exposed to H 2S. The adsorption of H 2S on the anode is dissociative and this dissociation can produce adsorbed sulfur. The dissociation potential of H 2S was studied by potential steps, and the values of the dissociation potential are about 0.4 V at 90 °C, 0.5 V at 60 °C and 0.6 V at 30 °C, respectively. The adsorbed sulfur can be oxidized at a higher potential. During CV scans, two oxidation peaks for the adsorbed sulfur at 1.07 and 1.2 V were observed at 90 °C, however a single oxidation peak could be observed at 1.2 V at 60 °C and at 1.27 V at 30 °C. Application of EIS to a H 2S|H 2 half-cell shows that the charge transfer resistance increases when the anode is exposed to H 2S because of H 2S adsorption.

Metal Carbide-Based Hydrodesulfurization Catalysts as Sulfur-Tolerant Electrocatalysts for PEMFC Anodes

Nanostructured nickel tungsten carbide (Ni6W6C) and nickel molybdenum carbide (Ni6Mo6C) are well known hydrodesulfurization catalysts, that have been speculated to be useful as sulfur-tolerant proton exchange membrane fuel cell anode catalysts. We synthesized these compounds and evaluated their electrocatalytic activities for the hydrogen oxidation reaction (HOR) in sulfur-free electrolyte as well as electrolyte contaminated with 31 μM mercaptosuccinic acid (1 ppm sulfur) using a rotating disk electrode. The HOR activity of the carbides is higher than that reported elsewhere, but still is low when compared to platinum catalysts. The nanostructured catalysts corrode and show poor sulfur tolerance. Further development is needed to understand why these catalysts perform poorly in fuel cell environments.