Hydrogen storage is widely recognized as a critical enabling technology for the successful commercialization and market acceptance of hydrogen powered vehicles. Storing sufficient hydrogen on-board a wide range of vehicle platforms, while meeting all consumer requirements (driving range, cost, safety, performance, etc.), without compromising passenger or cargo space, is a tremendous technical challenge. The U.S. Department of Energy (DOE), in collaboration with automotive industry partners, established specific technical targets for on-board hydrogen storage systems to focus R&D and to stimulate research on hydrogen storage. In order to achieve these long-term targets, DOE launched a ''Grand Challenge'' to the scientific community in 2003. Based on a competitively selected portfolio, DOE established a ''National Hydrogen Storage Project'' in the U.S. for R&D in the areas of advanced metal hydrides, chemical hydrogen storage, carbon-based and high surface area sorbent materials, as well as new materials and concepts. The current status of vehicular hydrogen storage is reviewed and research associated with the National Hydrogen Storage Project is discussed. Future DOE plans through the International Partnership for the Hydrogen Economy (IPHE) are also presented.

NASA is currently using a solid amine sorbent known as HSC + for regeneratively removing CO 2 in space shuttle applications. This sorbent may also be of value for CO 2 removal in various industrial processes such as greenhouse gas control, industrial syntheses, and natural gas purification. To design novel sorbents and to design a CO 2 scrubber based on HSC + , physical and thermochemical property data are required. In this paper, we present a detailed experimental investigation of property data and long-term performance results using HSC + as a CO 2 sorbent. Differential scanning calorimetry was used to determine the heat capacity of the material. Cyclic and equilibrium capacities of the material for CO 2 pickup were determined and long-term test data show excellent performance. In addition, we have determined the heat of adsorption associated with CO 2 pickup by HSC + and the effect of moisture, using isothermal flow calorimetry. We have also performed thermal gravimetric analyses on the materials to gain insight into the stability of the material and determine the temperatures at which CO 2 and constituents of HSC + leave the surface of the material.

The Electrochemical Society Interface • Spring 2018 • www.electrochem.org 47 M uch of hydrogen's value to the energy-system lies in its ability to be cleanly and efficiently converted between chemical and electrical energy, while also possessing the high energy density and longterm storage potential of chemical bonds. For these reasons, hydrogen's importance is expected to grow substantially in the coming decades, providing cross-sector and cross-temporal impact through clean, efficient processes. Many of these processes are electrochemical in nature, such as electrolysis of water and electricity production using fuel cells. Hydrogen also offers significant flexibility in how it can integrate into the energy system as a function of scale (from W to GWs), source (fossil fuels, nuclear, biomass, solar, wind, thermal), and end use (grid, buildings, industry, transportation). This flexibility, along with the ability to be used as a dispatchable load or power generation source, allows hydrogen and hydrogen-based processes to couple with the overall energy system in an integrated or hybridized fashion, offering system optimization potential. However, achieving the scale necessary to have impact-the vision of Hydrogen at Scale (H 2 @Scale)-still has research challenges, many of which center around electrochemistry.

When energized sufficiently either vibrationally or electronically, ROH (where R is methyl or ethyl) can dissociate to form H atoms and RO radicals. We have determined the translational energy release (〈ETr 〉=0.82Eavl ) and angular distribution (β=−0.60±0.03) from the laser induced fluorescence spectra of H atoms produced in the 193 nm photodissociation of CD3OH. We have also determined that the quantum yield for producing H from CD3OH is 0.86±0.10. In contrast, the reaction of O(1D)+CH4 which produces vibrationally excited CH3OH, has a quantum yield for producing H atoms of roughly 0.25 with only 22% of the available energy released as translation. We conclude that although the total available energy is the same in both cases, the dissociation of photoexcited methanol is prompt whereas the dissociation of chemically activated methanol shows some degree of internal vibrational equilibration.

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