DFT Study of Hydrogen Storage by Spillover on Graphite with Oxygen Surface Groups

Psofogiannakis, George; Froudakis, George E.

doi:10.1021/ja906159p

Cited by 114 publications

(119 citation statements)

References 11 publications

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“…It is ironic that, in recent years, hydrogen spillover has been more intensively studied in the field of hydrogen storage [8][9][10][11][12][13][14][15][16] rather than in heterogeneous catalysis where the hydrogen spillover concept was first demonstrated.I nh ydrogen storage, hydrogen spillover was used to enhancet he H 2 storage capacities of carbon-based materials by using the chemisorption of atomic hydrogen on their surface. To achieve the increased uptake of H 2 ,a tomic hydrogen generated on the metal catalysts urface should migrate to the carbon support (or adsorbent) surface to form sufficiently stable CÀH [12][13][14][15] and OÀH( with oxygen functional groups) bonds.…”

Section: Understanding Hydrogen Spillover From a Catalysis Point Of Viewmentioning

confidence: 99%

Hydrogen Spillover in Encapsulated Metal Catalysts: New Opportunities for Designing Advanced Hydroprocessing Catalysts

2015

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Hydrogen spillover has been one of the most debated concepts in the field of heterogeneous catalysis due to limited ways of studying it. The main controversies in hydrogen spillover, especially from the viewpoint of its catalytic functions, can be mainly attributed to the absence of well‐defined model catalysts that can provide direct proof of the catalytic functions of hydrogen spillover. In this article, we will provide an overview of the recent progress made with encapsulated metal catalysts, which can act as an ideal model catalyst for proving the existence and catalytic functions of hydrogen spillover. We will also demonstrate unique opportunities of using the encapsulated metal catalysts for designing advanced hydroprocessing catalysts with enhanced activity, distinct chemoselectivity, and increased catalyst durability.

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Section: Understanding Hydrogen Spillover From a Catalysis Point Of Viewmentioning

confidence: 99%

Hydrogen Spillover in Encapsulated Metal Catalysts: New Opportunities for Designing Advanced Hydroprocessing Catalysts

2015

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“…It has been proposed that accumulated hydrogen molecules on metal sites may be activated through catalysis and then spill over onto the otherwise inert surface, called the receptor (68)(69)(70)(71). Platinum nanoparticles are commonly used as catalysts, and activated carbon materials combined with MOFs have been tested as receptors.…”

Section: Spillover Of Hydrogen Onto Inert Surfacesmentioning

confidence: 99%

Progress on first-principles-based materials design for hydrogen storage

Park

Choi

Hwang

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

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This article briefly summarizes the research activities in the field of hydrogen storage in sorbent materials and reports our recent works and future directions for the design of such materials. Distinct features of sorption-based hydrogen storage methods are described compared with metal hydrides and complex chemical hydrides. We classify the studies of hydrogen sorbent materials in terms of two key technical issues: (i) constructing stable framework structures with high porosity, and (ii) increasing the binding affinity of hydrogen molecules to surfaces beyond the usual van der Waals interaction. The recent development of reticular chemistry is summarized as a means for addressing the first issue. Theoretical studies focus mainly on the second issue and can be grouped into three classes according to the underlying interaction mechanism: electrostatic interactions based on alkaline cations, Kubas interactions with open transition metals, and orbital interactions involving Ca and other nontransitional metals. Hierarchical computational methods to enable the theoretical predictions are explained, from ab initio studies to molecular dynamics simulations using force field parameters. We also discuss the actual delivery amount of stored hydrogen, which depends on the charging and discharging conditions. The usefulness and practical significance of the hydrogen spillover mechanism in increasing the storage capacity are presented as well. Renewable Energy and the Significance of Hydrogen StorageT he prosperity of modern civilization is inextricably based on energy supply networks (on-grid or off-grid) that deliver petroleum, natural gas, and electricity to residential, public, commercial, and industrial facilities, as well as transport systems. Concerns are growing over the limited availability of natural resources and the environmentally hazardous byproducts of the energy conversion process, such as greenhouse gases. From this perspective, renewable energy harvesting technologies based on natural energy flows, including solar power, wind power, geothermal energy, and tidal energy, are increasingly gaining momentum. The storage of the harvested energy remains a fundamentally important factor for the utilization of the renewable energy because the sources of the renewable energy usually undergo significant spatial and temporal variations (1). The issue of hydrogen storage can be understood in this context. Among chemical fuels, pure hydrogen (i.e., in the gas form) has the highest mass density but the poorest volumetric density (2, 3). As a result, hydrogen storage research traces a long history of studies toward the reversible condensation of hydrogen into a limited volume using lightweight devices. In recent decades a globally recognized objective is the development of a stored hydrogen carrier that can power vehicles through fuel cells (or, perhaps, combustion engines). For example, the guideline published by the US Department of Energy states that, for a commercially competitive vehicle, hydrogen storage systems ne...

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“…[8][9][10] In parallel, researchers have discussed the hydrogen spillover phenomena in which hydrogen atoms are claimed to be stored as chemisorption states after migration from catalytic metal sites. [11][12][13][14] …”

Section: Introductionmentioning

confidence: 99%

Stability of hydrogenation states of graphene and conditions for hydrogen spillover

Han

Jung

et al. 2012

Phys. Rev. B

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The hydrogen spillover mechanism has been discussed in the field of hydrogen storage and is believed to have particular advantage over the storage as metal or chemical hydrides. We investigate conditions for practicality realizing the hydrogen spillover mechanism onto carbon surfaces, using first-principles methods. Our results show that contrary to common belief, types of hydrogenation configurations of graphene (the aggregated all-paired configurations) can satisfy the thermodynamic requirement for room-temperature hydrogen storage. However, the peculiarity of the paired adsorption modes gives rise to a large kinetic barrier against hydrogen migration and desorption. It means that an extremely high pressure is required to induce the migration-derived hydrogenation. However, if mobile catalytic particles are present inside the graphitic interstitials, hydrogen migration channels can open and the spillover phenomena can be realized. We suggest a molecular model for such a mobile catalyst which can exchange hydrogen atoms with the wall of graphene.

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DFT Study of Hydrogen Storage by Spillover on Graphite with Oxygen Surface Groups

Cited by 114 publications

References 11 publications

Hydrogen Spillover in Encapsulated Metal Catalysts: New Opportunities for Designing Advanced Hydroprocessing Catalysts

Hydrogen Spillover in Encapsulated Metal Catalysts: New Opportunities for Designing Advanced Hydroprocessing Catalysts

Progress on first-principles-based materials design for hydrogen storage

Stability of hydrogenation states of graphene and conditions for hydrogen spillover

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