Hydrogen is an attractive energy option because of its low
environmental impact, but a critical problem is its low energy
density, which makes it difficult to store. For example, the US
Department of Energy (DOE) hydrogen plan for fuel cell powered
vehicles requires a gravimetric density of 6.5 wt%. There are several
existing hydrogen storage methods, including compressed gas,
liquefaction, metal hydrides, and physisorption, but at present, none
of these technologies comes close to achieving the targets set by the
DOE. Although chemical storage methods have been claimed to be the
most promising hydrogen storage technology, and activated carbons the
best adsorbent, as mentioned, chemical storage methods are still far
from the desired targets. In order to try to bring these chemical
storage methods closer to desired targets, research must be done to
find ways to maximize chemical storage potential using different
materials. Recently, there has been a resurgence of interest in the
potential of carbon materials. In order to try to move these hydrogen
storage goals further toward the goals of the DOE, numerous
experiments were done in altering the current materials to try to
maximize the hydrogen storage potential. Hydrogen Spillover, one
method currently being considered, is where a metal catalyst
dissociates hydrogen molecules into atomic hydrogen, which then
migrates down toward the carbon surface and is adsorbed onto the
carbon receptor. Experiments were done to compare the spillover
effects of multiple precious metals. Also, the use of basic high
surface area activated carbon (MSC-30) was compared to similar
activated carbons with Boron doping, with hopes of seeing an
enhancement of that spillover effect. Unfortunately, no significant
increases on the current storage capacity via spillover of ~1.2wt%
were achieved.


Chemical Engineering | Chemistry | Earth Sciences


Lin Simpson

Lab site

National Renewable Energy Laboratory (NREL)

Funding Acknowledgement

This material is based upon work supported by the S.D. Bechtel, Jr. Foundation and by the National Science Foundation under Grant No. 0952013. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the S.D. Bechtel, Jr. Foundation or the National Science Foundation. This project has also been made possible with support of the National Marine Sanctuary Foundation. The STAR program is administered by the Cal Poly Center for Excellence in Science and Mathematics Education (CESaME) on behalf of the California State University (CSU).



URL: http://digitalcommons.calpoly.edu/star/114


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