Hydrogen Uptake of Platinum-Doped Graphite Nanofibers and Stochastic Analysis of Hydrogen Spillover

Abstract

Graphite nanofibers (GNFs) were doped with platinum in an attempt to activate the materials for moderate temperature hydrogen adsorption. Characterization of the 1% Pt/GNF sample indicates well-dispersed, metallic platinum particles ranging from 2 to 5 nm in diameter. At 27 °C and 20 bar, the hydrogen uptake of 1% Pt/GNF was less than 0.1 wt % and showed no increase relative to the GNF precursor within experimental detection limits. To explore this apparent anomaly, a stochastic Monte Carlo simulation was used to analyze the hydrogen spillover process for idealized two-dimensional surfaces with two surface types with interfacial mass transfer from the first to the second surface site. The model suggests interfacial mass transfer may not improve overall surface coverage when the rates of adsorption and desorption to the support are comparable. Dimensionless groupings are introduced to the stochastic simulation to explore the conditions in which interfacial transfer will lead to significant surface coverage from a catalytically active surface to a previously inert surface. The implications for hydrogen storage are discussed..

Department(s)

Chemical and Biochemical Engineering

Sponsor(s)

Pennsylvania State University. Department of Energy & Geo-Environmental Engineering
Pennsylvania State University. College of Earth and Mineral Science
Pennsylvania State. Institutes for the Environment
Pennsylvania State University. Wilson Initiation Grant

Comments

The work was funded by The Pennsylvania State University's Department of Energy & Geo-Environmental Engineering, the College of Earth and Mineral Science, and The Pennsylvania State Institutes for the Environment. The modeling component was funded by a Wilson Initiation Grant from The Pennsylvania State University

Keywords and Phrases

Dimensionless groupings; Graphite nanofibers (GNFs); Hydrogen spillover; Interfacial mass transfer; Computer simulation; Graphite fibers; Hydrogen; Monte Carlo methods; Platinum; Semiconductor doping; Stochastic control systems; Two dimensional; Nanostructured materials

International Standard Serial Number (ISSN)

1932-7447

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2007 American Chemical Society (ACS), All rights reserved.

Publication Date

01 Jan 2007

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