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A Simple, Low-cost, and Robust System to Measure the Volume of Hydrogen Evolved by Chemical Reactions with Aqueous Solutions
Published on: August 17, 2016
Catalyzed hydrogen spillover for hydrogen storage.
1Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA. yang@umich.edu
Journal of the American Chemical Society
|March 3, 2009
Summary
Doping carbon sorbents with TiCl(3) or VCl(3) significantly enhances hydrogen storage rates. This breakthrough addresses key challenges in developing a hydrogen economy for transportation fuel cells.
Area of Science:
- Materials Science
- Chemical Engineering
- Energy Storage
Background:
- Hydrogen storage is critical for a hydrogen economy, especially for fuel cell vehicles.
- Current hydrogen storage methods face challenges with capacity and charge/discharge rates.
- Hydrogen spillover in sorbent materials shows promise but suffers from slow rates.
Purpose of the Study:
- To investigate methods for improving hydrogen spillover rates in sorbent materials.
- To assess the impact of metal salt doping on hydrogen adsorption and desorption kinetics.
- To analyze the effect of doping on hydrogen binding energies and isotherm properties.
Main Methods:
- Synthesis of doped sorbent materials using titanium(III) chloride (TiCl(3)) and vanadium(III) chloride (VCl(3)).
- Measurement of hydrogen adsorption and desorption rates using volumetric methods.
- Analysis of hydrogen isotherms to determine hysteresis and thermodynamic parameters.
- Calculation of heats of adsorption and activation energies for the spillover process.
Main Results:
- Doping with 2 wt % TiCl(3) or VCl(3) significantly increased hydrogen adsorption and desorption rates.
- The hysteresis loop in hydrogen isotherms was eliminated by doping.
- Heats of adsorption and activation energies for spillover were reduced upon doping.
- Doping decreased the binding energies between spilled-over hydrogen and carbon surface sites.
Conclusions:
- Metal salt doping is an effective strategy to enhance hydrogen spillover kinetics in sorbent materials.
- Reduced binding energies facilitate faster hydrogen uptake and release, crucial for fuel cell applications.
- This approach offers a pathway to meet U.S. Department of Energy targets for on-board hydrogen storage.
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