How Does Metal Hydride Formation Occur?

  • Thread starter Thread starter mess1n
  • Start date Start date
  • Tags Tags
    Formation Metal
AI Thread Summary
Metal hydride formation involves the dissociation of molecular hydrogen at metal surfaces, where hydrogen atoms are absorbed into the metal lattice and can later recombine into H2 during desorption. The concentration of hydrogen in the metal increases at specific pressures due to the interplay of hydrogen solubility and temperature, which affects how hydrogen diffuses through the metallic structure. Autocatalytic dissociation is a key theory explaining this process, highlighting the role of surface reactions in hydrogen absorption. Understanding these dynamics is crucial for grasping the behavior of metal hydrides, as detailed in relevant scientific literature.
mess1n
Messages
24
Reaction score
0
I'm very confused about how metal hydrides form. I'm looking at PCI plots and I see what's happening, but I have no idea why it is. For instance:

"Molecular hydrogen is dissociated at the surface before absorption; two H atoms recombine to H2 in the desorption process."

Why does this happen?

PCI Plot.gif


Also, I've attached a PCI plot. Can anyone explain why the concentration suddenly increases at certain pressures?

I've searched so many books and internet resources to try and find an explanation for these processes, to no avail, please help! :(


Andrew
 
Last edited:
Engineering news on Phys.org
Sorry to bump this, but I'm hoping someone sees it who will be able to help. Is this question in the right section?
 
There is a theory of autocatalytic dissociation of hydrogen in metals.
http://www.springerlink.com/content/f602850hk808h357/

And there is this
Hydrogen dissociation on metal surfaces – a model system for reactions on surfaces
Applied Physics A: Materials Science & Processing
Volume 67, Number 6, 627-635, DOI: 10.1007/s003390050834
A. Gross

Clearly to form hydrides, the proton has to diffuse through the metallic grains/crystal structure. The solubility of hydrogen in a metal is temperature dependent.
 
Thanks so much for the reply, I'll read through those articles now.
 
Back
Top