DOE's Office of Science, through its Office of Basic Energy Sciences, seeks to foster revolutionary advances in hydrogen production, delivery, storage, and conversion technologies to close the gap between today's knowledge and technology and tomorrow's clean energy economy. Recent advances in nanosciences, catalysis, modeling, simulation, and bio-inspired approaches offer exciting new research opportunities for a variety of hydrogen and fuel cell technologies. By emphasizing cross-cutting research directions, and promoting broad interdisciplinary efforts, strong coordination between the basic and applied sciences, and cooperation among BES and the Offices of Energy Efficiency and Renewable Energy, Fossil Energy and Nuclear Energy, scientific breakthroughs in one area can be leveraged to advance progress in others.
This integrated approach will ensure that discoveries and related conceptual breakthroughs achieved in basic research programs will provide a foundation for the innovative design of materials and processes that will produce improvements in the performance, cost, and reliability of hydrogen production, storage, and use.
The priority basic research areas identified in this report include:
Priority Research Areas for Hydrogen Production, Storage and Fuel Cells
Novel Materials for Hydrogen Storage
On-board hydrogen storage is considered to be the most challenging aspect for the successful transition to a hydrogen economy. Basic research is essential for identifying novel materials and processes that can provide potential breakthroughs needed to meet the Hydrogen Fuel Initiative (HFI) goals.
Complex hydrides. A basic understanding of the physical, chemical, and mechanical properties of metal hydrides and chemical hydrides is needed.
Nanostructured materials. Tailored nanostructures need to be explored since nanophase materials offer promise for superior hydrogen storage due to short diffusion distances, new phases with better capacity, reduced heats of adsorption/desorption, faster kinetics, and surface states capable of catalyzing hydrogen dissociation.
Other materials. Research is needed to explore other novel storage materials, e.g., those based on nitrides, imides, and other materials that fall outside of metal hydrides, chemical hydrides, and carbon-based hydrogen storage materials.
Theory, modeling, and simulation. Theory, modeling, and simulation will enable (1) understanding the physics and chemistry of hydrogen interactions at the appropriate size scale and (2) the ability to simulate, predict, and design materials performance in service.
Novel analytical and characterization tools. Sophisticated analytical techniques are needed to meet the high sensitivity requirements associated with characterizing hydrogen-materials interactions while maintaining high specificity.
Membranes for Separation, Purification, and Ion Transport
Membranes that selectively transport atomic, molecular, or ionic hydrogen and oxygen are vital to the hydrogen economy as they purify hydrogen fuel streams, transport hydrogen or oxygen ions between electrochemical half-reactions, and separate hydrogen in electrochemical, photochemical, or thermochemical production routes.
Integrated nanoscale architectures. The similar nanoscale dimensions of catalyst particles and of pores that transport fuel, ions, and oxygen hold promises to enable gas diffusion layers, catalyst support networks, and electrolytic membranes in fuel cells to be integrated into a single network for ion, electron, and gas transport.
Fuel cell membranes. Novel membranes with higher ionic conductivity, better mechanical strength, lower cost, and longer life are critical to the success of fuel cell technologies.
Theory, modeling, and simulation of membranes and fuel cells. The diversity of transport mechanisms and their dependence on local defect structure requires extensive theory, modeling and simulation to establish the basic principles and design strategies for improved membrane materials.
Design of Catalysts at the Nanoscale
Catalysis is vital to the success of the HFI owing to its roles in converting solar energy to chemical energy, producing hydrogen from water or carbon-containing fuels such as coal and biomass, and producing electricity from hydrogen in fuel cells. Catalysts can also increase the efficiency of the uptake and release of stored hydrogen with reduced need for thermal activation. Breakthroughs in catalytic research would impact the thermodynamic efficiency of hydrogen production, storage, and use, and thus improve the economic efficiency with which the primary energy sources — fossil, biomass, solar, or nuclear — serve our energy needs.
Nanoscale catalysts. Nanostructured materials — with high surface areas and large numbers of controllable sites that serve as active catalytic regions — open new opportunities for significantly enhancing catalytic activity and specificity.
Innovative synthetic techniques. Emerging technologies that allow synthesis at the nanoscale with atomic-scale precision will open new opportunities for producing tailored structures of catalysts on supports with controlled size, shape and surface characteristics. New, high-throughput innovative synthesis methods can be exploited in combination with theory and advanced measurement capabilities to accelerate the development of designed catalysts.
Novel characterization techniques. To fully understand complex catalytic mechanisms will require detailed characterization of the active sites; identification of the interaction of the reactants, intermediates and products with the active sites; conceptualization and, possibly, detection of the transition states; and quantification of the dynamics of the entire catalytic process.
Theory, modeling, and simulation of catalytic pathways. Close coupling between experimental observations and theory, modeling, and simulation will provide unprecedented capabilities to design more selective, robust, and impurity-tolerant catalysts for hydrogen production, storage, and use.
Solar Hydrogen Production
Efficient conversion of sunlight to hydrogen by splitting water through photovoltaic cells driving electrolysis or through direct photocatalysis at energy costs competitive with fossil fuels is a major enabling milestone for a viable hydrogen economy.
Nanoscale structures. The sequential processes of light collection, charge separation, and transport in photovoltaic and photocatalytic devices require nanoscale architectural control and manipulation. Light harvesting and novel photoconversion concepts. New strategies are needed to efficiently use the entire solar spectrum.
Organic semiconductors and other high performance materials. The organic semiconductors offer an inexpensive alternative to traditional semiconductors for photovoltaic and photocatalytic devices.
Theory, modeling, and simulation of photochemical processes. Theory and modeling are needed to develop a predictive framework for the dynamic behavior of molecules, complex photoredox systems, interfaces, and photoelectrochemical cells.
Bio-inspired Materials and Processes
Fundamental research into the molecular mechanisms underlying biological hydrogen production is the essential key to our ability to adapt, exploit, and extend what nature has accomplished for our own renewable energy needs.
Enzyme catalysts. A fundamental understanding is needed of the structure and chemical mechanism of enzyme complexes that support hydrogen generation.
Bio-hybrid energy coupled systems. As more is understood about biocatalytic hydrogen production, there is the possibility that critical enzymes that are synthesized and employed by biological systems can be harvested and combined with synthetic materials to construct robust, efficient hybrid systems that are scalable to hydrogen production facilities.
Theory, modeling, and nanostructure design. Taking cues from these various natural processes, computational approaches may be employed for rational redesign of enzymes for improved hydrogen production, reduced sensitivity to inhibitors, and improved stability.
Patricia M. Dehmer
Office of Basic Energy Sciences (SC-22)
U.S. Department of Energy
Washington, DC 20585-1290