Florida Hydrogen Initiative (FHI) (Final Report)

This paper reports proposed efforts to develop a program focused on Hydrogen and Fuel Cell Technology (HFCT) in Engineering Technology Department (ENT) jointly with the Florida Solar Energy Center (FSEC) at University of Central Florida (UCF). The HFCT Program intends to support the need for educated graduates that comprise the next generation workforce needed for research, development, and demonstration activities in government, industry, and academia. The proposed project will include the development and delivery of undergraduate courses at Engineering Technology Department and FSEC within the ABET accredited Bachelor of Science in Engineering Technology (BSET) program. The mode of course offering will be both in class and on line, which will increase the number of students. The proposed project facilitates are located at College of Engineering and Computer Science (CECS) and at FSEC of UCF. The Florida Solar Energy Center is a unique component of the proposed effort. FSEC has been conducting hydrogen and fuel cell research for 25 years and FSEC has dedicated facilities and a selection of unique laboratory equipment that will be made available to the students for this project. These attributes will allow the students to be trained on the state-of-the-art equipment and facilities. Both ENT and FSEC faculties will participate in the teaching and training of the prospective students.

Rod Borup is a Team Leader in the fuel cell program at Los Alamos National Lab in Los Alamos, New Mexico. He received his B.S.E. in Chemical Engineering from the University of Iowa in 1988 and his Ph.D. from the University of Washington in 1993. He has worked on fuel cell technology since 1994, working in the areas of hydrogen production and PEM fuel cell stack components. He has been awarded 12 U.S. patents, authored over 40 papers related to fuel cell technology, and presented over 50 oral papers at national meetings. His current main research area is related to water transport in PEM fuel cells and PEM fuel cell durability. Recently, he was awarded the 2005 DOE Hydrogen Program R&D Award for the most significant R&D contribution of the year for his team's work in fuel cell durability and was the Principal Investigator for the 2004 Fuel Cell Seminar (San Antonio, TX, USA) Best Poster Award. Jeremy Meyers is an Assistant Professor of materials science and engineering and mechanical engineering at the University of Texas at Austin, where his research focuses on the development of electrochemical energy systems and materials. Prior to joining the faculty at Texas, Jeremy workedmore » as manager of the advanced transportation technology group at UTC Power, where he was responsible for developing new system designs and components for automotive PEM fuel cell power plants. While at UTC Power, Jeremy led several customer development projects and a DOE-sponsored investigation into novel catalysts and membranes for PEM fuel cells. Jeremy has coauthored several papers on key mechanisms of fuel cell degradation and is a co-inventor of several patents. In 2006, Jeremy and several colleagues received the George Mead Medal, UTC's highest award for engineering achievement, and he served as the co-chair of the Gordon Research Conference on fuel cells. Jeremy received his Ph.D. in Chemical Engineering from the University of California at Berkeley and holds a Bachelor's Degree in Chemical Engineering from Stanford University. Bryan Pivovar received his B.S. in Chemical Engineering from the University of Wisconsin in 1994. He completed his Ph.D. in Chemical Engineering at the University of Minnesota in 2000 under the direction of Profs. Ed Cussler and Bill Smyrl, studying transport properties in fuel cell electrolytes. He continued working in the area of polymer electrolyte fuel cells at Los Alamos National Laboratory as a post-doc (2000-2001), as a technical staff member (2001-2005), and in his current position as a team leader (2005-present). In this time, Bryan's research has expanded to include further aspects of fuel cell operation, including electrodes, subfreezing effects, alternative polymers, hydroxide conductors, fuel cell interfaces, impurities, water transport, and high-temperature membranes. Bryan has served at various levels in national and international conferences and workshops, including organizing a DOE sponsored workshop on freezing effects in fuel cells and an ARO sponsored workshop on alkaline membrane fuel cells, and he was co-chair of the 2007 Gordon Research Conference on Fuel Cells. Minoru Inaba is a Professor at the Department of Molecular Science and Technology, Faculty of Engineering, Doshisha University, Japan. He received his B.Sc. from the Faculty of Engineering, Kyoto University, in 1984 and his M.Sc. in 1986 and his Dr. Eng. in 1995 from the Graduate School of Engineering, Kyoto University. He has worked on electrochemical energy conversion systems including fuel cells and lithium-ion batteries at Kyoto University (1992-2002) and at Doshisha University (2002-present). His primary research interest is the durability of polymer electrolyte fuel cells (PEFCs), in particular, membrane degradation, and he has been involved in NEDO R&D research projects on PEFC durability since 2001. He has authored over 140 technical papers and 30 review articles. Kenichiro Ota is a Professor of the Chemical Energy Laboratory at the Graduate School of Engineering, Yokohama National University, Japan. He received his B.S.E. in Applied Chemistry from the University of Tokyo in 1968 and his Ph.D. from the University of Tokyo in 1973. He has worked on hydrogen energy and fuel cells since 1974, working on materials science for fuel cells and water electrolysis. He has published more than 150 original papers, 70 review papers, and 50 scientific books. He is now the president of the Hydrogen Energy Systems Society of Japan, the chairman of the Fuel Cell Research Group of the Electrochemical Society of Japan, and the chairman of the National Committee for the Standardization of the Stationary Fuel Cells. ABSTRACT TRUNCATED« less

High Temperature Proton Exchange Membrane Fuel Cells (HT-PEMFC) can reject very small quantities of phosphoric acid due to the ageing of their electrolyte. Also, as a preventive measure, the tests performed with this technology are often not pressure-regulated to prevent the outlet valve opening from clogging in case of acid leakage. In this configuration, atmospheric pressure variations lead to pressure changes in both fuel cell anode and cathode compartments, these pressure variations themselves generating cell voltage variations. The work presented in this article introduces a readjustment method for the fuel cell voltage according to the variations of the operating conditions. This readjustment is based on the realization of a design of experiments to characterize the voltage sensitivity to the ambient pressure and temperature of a commercial membrane electrode assembly (MEA, BASF Celtec®-P 1100W type). An empirical model is identified from these experimental data obtained. It is then used to generate the compensating coefficients to smooth the impact of variations in operating conditions. Finally, the readjustment method is applied and discussed to the fuel cell voltage for a test example.

Longevity is a key criterion for the future success of fuel cells in challenging markets like the automotive drive train as it contributes to cost and user experience. The analysis of degradation processes is therefore currently in the focus of research. It is known, that several degradation processes exist, which over time can cause the failure of LT-PEMFC. Examples are changes in the structure of the catalyst particles due to effects like platinum dissolution or Ostwald ripening, the loss of catalyst particles due to corrosion of the carbon support or thinning and pinhole formation of the membrane due to attack by radicals and other detrimental intermediates. A number of test protocols exists which try to selectively test for the influence of one particular degradation process. Thereby the different degradation processes are assigned to vehicle operation conditions as described e.g. by Ohma et al. for the Fuel Cell Commercialization Conference of Japan (FCCJ) test protocols1. Common assignments are e.g. the tests of platinum particle degradation to driving at variable loads as it is tested with voltage jumps between 0.6 V and 1.0 V or the membrane degradation to standby as it is tested by potential hold at OCV. The carbon corrosion tests, which usually are assigned to system start-stop and are performed by fast potential cycling between 1.0 V and 1.5 V. the assignment as well as the selected potential window is derived from the results of Reiser et al.2, who found very high potential for the transient situation that anode and cathode are both filled with air when hydrogen is admitted to the cathode for the system start. This situation also often referred to as air/air start, can indeed occur in the operation of an automotive fuel cell stack. However, as it is due to longer standstill of the vehicle, it will happen at the vehicle ambient temperature which is likely 20 °C or below. The effect of temperature on degradation processes at fuel cell catalyst and fuel cell membrane electrode assemblies has been studied before also by our group3 but usually with focus to elevated temperatures well above ambient temperature. Publication of results even on catalyst activity for the relevant temperature window between 0 °C and 20 °C are scarce and even less exist which include degradation effect. Here we will present on test series in which we studied a commercial Pt/C fuel cell catalysts, both at RDE and single cell level, in the temperature window between 0 °C and 20 °C. In Figure 1 results on the RDE measurement at different temperatures are depicted. As can be seen in figure 1 a), the direct effect of the temperature on the performance is simply a reduced activity without changes in the Tafel slopes. If the carbon corrosion test is performed at different temperatures the change of the electrochemical surface area (ECSA) determined by evaluation of the HUPD part of the CV differs for the different temperatures. At all temperatures the carbon corrosion test causes a slight increase in ECSA following the first sets of stress cycles followed by a severe decay. Now, at lower temperatures this initial increase is stronger and endures longer than at 20 °C. Also the final decay is much more important at 20 °C than at 10 °C or 0 °C. In contrast to this finding, the kinetic current density at 0.9 V after the entire set of 20.000 cycles shows a stronger increase at 20 °C than at the lower temperatures (cf. figure 1 c). As the current density after the stress cycles is normalised to the remaining surface area, it means that the remaining catalyst has a higher activity. In this context, the results of the CO stripping before and after the stress tests shown in figure 1 d) are of interest. Here it is found that the carbon corrosion tests cause the evolution of a pre-peak oxidation area for CO which according to Maillard et al.4 is indicating the presence of particle agglomerates. This behaviour is much lower if the stress test is performed at lower temperatures. In the presentation further results, including test on commercial Pt3Co/C catalyst and single cell tests will be reported. A. Ohma, K. Shinohara, A. Iiyama, T. Yoshida, and A. Daimaru, ECS Trans., 41(1), 775–784 (2011)C. A. Reiser et al., Electrochem. Solid-State Lett., 8, A273–A276 (2005)C. Cremers et al., J. Electrochem. Soc., 165 (2018)F. Maillard et al., Phys. Chem. Chem. Phys., 7, 385–393 (2005) Figure 1

The 2015 Annual Progress Report summarizes fiscal year 2015 activities and accomplishments by projects funded by the DOE Hydrogen and Fuel Cells Program. It covers the program areas of hydrogen production; hydrogen delivery; hydrogen storage; fuel cells; manufacturing R&D; technology validation; safety, codes and standards; systems analysis; and market transformation.

Experimental study of the potential degradation due to the polarization curve of a high temperature proton exchange membrane fuel cell

Magnesium-based hydrogen storage alloys have attracted significant attention as promising materials for solid-state hydrogen storage due to their high hydrogen storage capacity, abundant reserves, low cost, and reversibility. However, the widespread application of these alloys is hindered by several challenges, including slow hydrogen absorption/desorption kinetics, high thermodynamic stability of magnesium hydride, and limited cycle life. This comprehensive review provides an in-depth overview of the recent advances in magnesium-based hydrogen storage alloys, covering their fundamental properties, synthesis methods, modification strategies, hydrogen storage performance, and potential applications. The review discusses the thermodynamic and kinetic properties of magnesium-based alloys, as well as the effects of alloying, nanostructuring, and surface modification on their hydrogen storage performance. The hydrogen absorption/desorption properties of different magnesium-based alloy systems are compared, and the influence of various modification strategies on these properties is examined. The review also explores the potential applications of magnesium-based hydrogen storage alloys, including mobile and stationary hydrogen storage, rechargeable batteries, and thermal energy storage. Finally, the current challenges and future research directions in this field are discussed, highlighting the need for fundamental understanding of hydrogen storage mechanisms, development of novel alloy compositions, optimization of modification strategies, integration of magnesium-based alloys into hydrogen storage systems, and collaboration between academia and industry.

Research on ammonia borane (AB, NH3BH3) has shown it to be a promising material for chemical hydrogen storage in PEM fuel cell applications. AB was selected by DOE’s Hydrogen Storage Engineering Center of Excellence (HSECoE) as the initial chemical hydride of study because of its high hydrogen storage capacity (up to 19.6% by weight for the release of three molar equivalents of hydrogen gas) and its stability under typical ambient conditions. A model of a bead reactor system was developed to study AB system performance in an automotive application and estimate the energy, mass, and volume requirements for this off-board regenerable hydrogen storage material. The system includes feed and product tanks, hot and cold augers, a ballast tank/reactor, a H2 burner and a radiator. One-dimensional models based on conservation of species and energy were used to predict important state variables such as reactant and product concentrations, temperatures of various components, flow rates, and pressure in the reactor system. The flow rate of AB into the process and the system pressure were governed by a control system which is modeled as an independent subsystem. Each subsystem in the model was coded as a C language S-function and implemented in the Matlab/Simulink environment. Preliminary system simulation results for a start-up case and for a transient drive cycle indicate appropriate trends in the reactor system dynamics.

Commercialization of technology of PEMFC (proton electron membrane fuel cells) remains a big obstacle regardless of the broad research on PEM and other fuel cells.High temperature proton exchange fuel cell has found its wide application now days and it is very important to manage the Heat and apply cooling arrangement for the fuel cell stack as durability is at stake when exposed for the longer duration. Considering the heat sources HT-PEM has three heat sources: 1) irreversible joule heating caused by the charge transport in the solid electrolyte or the conductor 2) Reversible heating due to the charge entropy change and 3) irreversible heating of the reaction caused due to the over potential. Considering all the aspect it is found that the optimum temperature for HT PEM Fuel cell is 170℃ to 180℃ though it is observed that at 200℃ the efficiency has shown positive effect. The enormous heat generated by the electrochemical reaction of the fuel cell as a by-product and when it reaches to the extreme limit of the recommended temperature which makes cooling necessary and based on the FC power the cooling strategy is to be implemented accordingly, Even though there are many methods for cooling but the medium through which the cooling takes place is restricted to 2 i.e. Air and Liquid..

One of the promising application areas for high temperature proton exchange membrane technology is as a range extender in a battery electric vehicle. Unlike low temperature PEM fuel cells dependent on perfluorosulfonic acid type membranes, HT-PEM fuel cells need no humidification, the conductivity of the membrane having much lower dependence on degree of hydration, and their use therefore eliminates water management issues. The operation conditions of a fuel cell for range extender application differ from those when the PEMFC stack is used for the power train. Thus the stack is subjected less to transients and operates in semi-continuous mode, but with stop/start events corresponding to the normal start up and shut down of vehicle operation. HT-PEM membranes are based upon polybenzimidazole (PBI) polymers that are doped with (generally) phosphoric acid. This acid "doping" may be achieved by immersion of a polymer membrane in acid, or by methods involving the preparation of the PBI polymer in polyphosphoric acid followed by membrane casting and a controlled hydrolysis step, or the dissolution of PBI in a polyphosphoric acid/phosphoric acid followed by membrane casting, in a thermoreversible sol-gel transition. The last two approaches lead to very high acid contents, easily exceeding 20 molecules H3PO4/PBI repeat unit, and the resulting membrane is soft with poor mechanical properties. Polymer cross-linking is a recognized means for improving membrane strength. To date, in the case of PBI, acid doping has been carried out on the cross-linked membrane, resulting in low phosphoric acid uptake. We have developed an approach that allows the covalent cross-linking of PBI by introduction of a molecular cross-linking species at the polymer dissolution stage, following by membrane casting and thermal curing to give the cross-linked membrane. Since this approach provides mechanical stabilization to an acid-swollen membrane containing a high content of acid, it is a means leading to highly proton conducting membranes of satisfactory mechanical properties. A range of synthesis parameters including the amount of cross-linking, temperature for thermal curing etc., have been examined and, most recently, we have provided experimental evidence for cross-linking with the help of X-ray photoelectron and nuclear magnetic resonance spectroscopies. Membrane electrode assemblies (MEAs) have been developed using the novel cross-linked acid doped PBI membranes, and fuel cell test protocols relevant to range extender application, based upon load cycling at 160 °C, have been applied. The results demonstrate that the novel MEAs comprising cross-linked PBI have lower voltage decay on load cycling than is observed using commercial MEAs, reaching >1000 h operation without the voltage dipping below the end-of-life criterion. The research leading to these results has received funding from the European Community’s Seventh Framework Programme for the Fuel Cells and Hydrogen Joint Undertaking under grant agreement ARTEMIS no. 303482.

High-temperature polymer electrolyte fuel cells (HT-PEFCs) are a suitable technology for decentralized small scale electricity and heat production. HT-PEFCs do not require hydrogen infrastructure and are characterized by a simpler and therefore less expensive system compared to available fuel cell systems. In combination with a reformer unit, HT-PEFC systems offer an efficiency gain over conventional combustion of hydrocarbons, such as natural gas. In near future, HT-PEFCs will be even more effective and efficient when renewable biofuels and hydrogen are widespread available. We present an efficient HT-PEFC based combined heat and power (µ-CHP) system for the provision of electrical energy and hot water in single family households (see Table 1). Due to the optimized design and layout of the fuel cell based µ-CHP system and the respective manufacturing processes of the catalysts and the membrane electrode assemblies (MEA), the demand for cost effective and greenhouse gas efficient energy at customer level is addressed. Major efforts were devoted to the establishment of scalable catalyst deposition methods, which enable a loss-free utilization of precious metals. By using appropriate multimetallic catalyst systems at anode and cathode, the precious metal loading was reduced by approx. 20% in comparison to commercially available electrodes without compromising performance (see Figure 1) [1]. Furthermore, by introducing post-preparation treatments, the stability of the catalysts was enhanced over commercial Pt/C. The activity and stability of the catalyst systems were evaluated ex situ by means of cyclic voltammetry and accelerated stress tests using a rotating disk electrode (RDE) setup. Furthermore, the catalyst systems were characterized in situ by means of polarization curves, continuous operation, accelerated stress tests and electrochemical impedance spectroscopy measurements at single cell, stack and at system level (see Figure 1). Acknowledgment Financial support was provided by The Climate and Energy Fund of the Austrian Federal Government and The Austrian Research Promotion Agency (FFG) through the program Energieforschung (e!Mission). [1] A. Schenk, C. Grimmer, M. Perchthaler, S. Weinberger, B. Pichler, C. Heinzl, C. Scheu, F.-A. Mautner, B. Bitschnau, V. Hacker, Platinum–cobalt catalysts for the oxygen reduction reaction in high temperature proton exchange membrane fuel cells – Long term behavior under ex-situ and in-situ conditions, J. Power Sources. 266 (2014) 313–322. Figure 1

At the Florida Solar Energy Center (FSEC), a research program is underway for developing a high-density hydrogen storage system based on amine-borane (AB) complexes. Due to their high hydrogen capacity, these hydrides have been employed, in the past, as disposable hydrogen sources for fuel cell applications. However, to meet the requirements for hydrogen storage onboard vehicles, it is essential that cost effective and energy efficient methods for the regeneration (i.e. hydrogenation) of the spent (dehydrogenated) AB complexes can be found that utilize only hydrogen and/or electricity (i.e. the only plausible hydrogen economy energy carriers).We are studying two ammoniaborane (NH3BH3)-based systems with high hydrogen storage capacity. The first system employs a borazine-cyclotriborazane cycle. Borazine is a product of NH3BH3 thermolysis. Cyclotriborazane is the inorganic analog of cyclohexane. The second system employs polymeric AB complexes such as poly-(aminoborane) and polyborazylene. Poly-(aminoborane), an inorganic analog of polyethylene, is also a product of amoniaborane thermolysis whilepolyborazylene is the product of borazine thermolysis.For the two systems above, we are developing regeneration (i.e. reduction of borazine, poly-(aminoborane) and polyborazylene) schemes based on: 1) catalytic hydrogenation and 2) indirect (multi-step) synthesis techniques.

<div class="section abstract"><div class="htmlview paragraph">One of the most critical elements in engineering a hydrogen fuel cell vehicle is the design of the on-board hydrogen storage system. Because the current compressed-gas hydrogen storage technology has several key challenges, including cost, volume and capacity, materials-based storage technologies are being evaluated as an alternative approach. These materials-based hydrogen storage technologies include metal hydrides, chemical hydrides, and adsorbent materials, all of which have drawbacks of their own. To optimize the engineering of storage systems based on these materials, it is critical to understand the impacts these systems will have on the overall vehicle system performance and what trade-offs between the hydrogen storage systems and the vehicle systems might exist that allow these alternative storage approaches to be viable.</div><div class="htmlview paragraph">To gain a better understanding of the interactions that exist between various materials-based hydrogen storage systems and the vehicle system as well as the engineering challenges that exist when integrating one of these systems with a vehicle, the National Renewable Energy Laboratory (NREL) developed a vehicle-level model designed to be sensitive to these issues. The Hydrogen Storage Simulation Model (HSSIM) was developed under the Hydrogen Storage Engineering Center of Excellence (HSECoE) as a specialized tool that could be used to assist in the design and engineering of materials-based hydrogen storage systems being considered by the HSECoE. This tool is designed to not only allow for understanding key trade-offs, but also to have a seamless integration with the HSECoE fuel cell and detailed hydrogen storage system models and to evaluate progress towards the U.S. Department of Energy's hydrogen storage technical targets. This model has been integrated with a fuel cell model developed by Ford Motor Company in a HSECoE common modeling framework developed by United Technologies Research Center and other HSECoE partners.</div><div class="htmlview paragraph">This paper focuses on the development, structure, and validation of the vehicle model HSSIM and summarizes its integration within the framework. HSSIM and the framework are then used to obtain trade-offs for various specific materials-based storage system designs. This includes hydrogen storage sizing analyses, mass compounding analyses, range versus volume studies, and vehicle and component performance analyses, such as acceleration rates and fuel cell and energy storage interactions.</div></div>

The aviation industry is facing one of its greatest challenges: how to reduce its CO2 emissions in the context of a constantly increasing air traffic. High Temperature Proton Exchange Membrane Fuel Cell (HT-PEMFCs) technology is of great interest for aviation, due to its easier thermal management, a simplified water management system and lower weight. However, the current Membrane Electrode Assembly (MEA) of HT-PEMFCs operating at 160°C are not at the expected level of performance. In this context, the NIMPHEA project aims to develop a new generation of HT MEAs at temperatures above 120°C to meet the demanding requirements of aviation fuel cells. HT-PEMFCs typically use phosphoric acid doped polybenzimidazole (PA-PBI). However, PA-PBI-based fuel cells have limited stability in the presence of water or at higher operating temperatures. In fact, they suffer from phosphoric acid loss. Recently, HT-PEMFCs based on quaternary ammonium bisphosphate Ion-Pair coordination (Ion-Pair) have shown better phosphoric acid retention in the temperature range of 80-200°C than PBI ones. In the frame of NIMPHEA project, we worked on the development of MEA based on Advent's Ion-Pair membrane technology for HT-PEMFCs. After optimizing the composition of both the cathode and anode active layers and the gas diffusion layer, we obtained a fuel cell with a nominal power density of 0.8 W/cm² at 180°C under H2/Air at 1 bar exceeding the performance of standard PBI based HT-PEMCs based MEA. This project has received funding from the Clean Hydrogen Joint Undertaking under grant agreement No 101101407. This Joint Undertaking receives support from the European Union’s Horizon Europe research and innovation program and Hydrogen Europe and Hydrogen Europe Research. The authors also thanks Advent technologies for their participation . Funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union. Neither the European Union nor the granting authority can be held responsible for them. Figure 1

The world is moving toward sustainable and low-carbon energy systems, which means we need hydrogen storage solutions that are safe, scalable, and cost-effective. Among several methods, solid-state hydrogen storage has become a promising alternative to traditional gaseous and liquid storage methods because it has a higher gravimetric capacity, is more stable, and is safer. This chapter delineates a computational analysis of perovskite hydrides XYH3 (X = Li, Na, K) employing first-principles density functional theory (DFT). The study thoroughly investigates their structural, electrical, optical, and mechanical properties to assess their viability for hydrogen storage applications. LiYH3, NaYH3, and KYH3 have lattice constants of 4.42 Å, 4.30 Å, and 4.41 Å, and their gravimetric hydrogen storage capacities are 3.06 wt%, 2.64 wt%, and 2.31 wt%, respectively. Thermodynamic study showed that the formation enthalpies were negative (−16.19 eV, −13.54 eV, and − 9.13 eV), which confirmed their stability. The Gibbs free energy values at 1000 K were also still good (−0.51 eV, −0.69 eV, and − 1.48 eV). The mechanical investigation showed that Young’s moduli were 27.59 GPa, 52.19 GPa, and 49.29 GPa, and all of the compounds were brittle (B/G < 1.75). Optical tests revealed significant absorption peaks between 26 and 29 eV, underscoring their suitability for optoelectronic applications. These findings underscore that perovskite hydrides are promising candidates for next-generation hydrogen storage devices, providing computationally informed design principles that enhance experimental initiatives. This combination of simulation and materials engineering helps create solid-state hydrogen storage solutions that are efficient, long-lasting, and cheap, which is important for the growth of the hydrogen economy.