5 years ago

Magnetic Moment Controlling Desorption Temperature in Hydrogen Storage: A Case of Zirconium-Doped Graphene as a High Capacity Hydrogen Storage Medium

Magnetic Moment Controlling Desorption Temperature in Hydrogen Storage: A Case of Zirconium-Doped Graphene as a High Capacity Hydrogen Storage Medium
M. R. Press, Brahmananda Chakraborty, Lavanya M. Ramaniah, N. Patel, A. Yadav, Abhijeet Gangan
For the first time, we predict through density functional theory that a single Zr atom attached on graphene surface can adsorb maximum of 9 H2 molecules with average binding energy of 0.34 eV and average desorption temperature of 433 K leading to a wt % of 11, higher than the DoE’s requirement of 6.5 wt %.The dependency of desorption temperature (TD) of H2 molecule with the magnetic moment (μ) of the system was exclusively studied by formulating the empirical relation TD = T0 + b (with T0 = 399 K, a = 302.38 J–1 T K and b = 0.5). For a system with a large magnetic moment, the charge transfer to the hydrogen molecule is higher, leading to higher desorption temperature (may be higher than prescribed limit for hydrogen storage by DoE). As the magnetic moment reduces, TD comes into the desired window for fuel cell applications. It can be inferred from this study that controlling the magnetic character of the system through doping may be an effective way to bring TD in to the desired window. We qualitatively and extensively demonstrate through the analysis of the partial density of states and Bader charge transfer the interaction mechanism of Zr on graphene surface and hydrogen storage capability of Zr decorated graphene. As we have used GGA exchange correlations (LDA over binds the system), checked the stability through ab initio MD simulations, computed the diffusion barrier for avoiding metal–metal clustering, and predicted that the hydrogen wt % of the system (11 wt %) comes higher than the DoE’s requirement (6.5 wt %) with desorption temperature (433 K) and is very much suitable for fuel cell applications, we strongly believe that Zr-doped graphene can be tailored as a high capacity hydrogen storage device.

Publisher URL: http://dx.doi.org/10.1021/acs.jpcc.7b04886

DOI: 10.1021/acs.jpcc.7b04886

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.