Adsorption of hydrogen by palladium

[verdigris]

How does hydrogen gas get into a piece of palladium metal such that the amount of hydrogen is 900 times the volume of palladium?A strong pump would be required to put 900 times the volume of a gas cylinder into the cylinder or the hydrogen would have to have its temperature lowered first.
Heat is evolved as hydrogen goes into the palladium - is this the hydrogen being cooled or pd-h bonds forming?

 

[haiha]

I do not if there's any Pd-H bond formed when H2 comes into palladium, but part of the heat is due to the entropy following the term : T*deltaS.
Volume is reduced and so is entropy.

 

[ravenprp]

The process of adsorption involves the physical attraction of gas molecules to the surface of a solid material, in this case, palladium. The high surface area of palladium allows for a large number of hydrogen molecules to be adsorbed, resulting in a high adsorption capacity. This means that for a given volume of palladium, a large amount of hydrogen gas can be adsorbed.

The mechanism by which hydrogen gas gets into the palladium metal is through diffusion. Hydrogen molecules, being small and highly mobile, can easily penetrate the surface of palladium and enter into the metal lattice. Once inside, they can form bonds with palladium atoms, resulting in the release of heat. This heat is a result of the exothermic process of bond formation between hydrogen and palladium.

To achieve an adsorption capacity of 900 times the volume of palladium, a strong pump would indeed be required to compress the hydrogen gas and force it into the metal. Alternatively, the temperature of the hydrogen gas could be lowered, reducing its volume and making it easier to adsorb into the palladium. However, this would also decrease the amount of heat released during the adsorption process.

In summary, the high adsorption capacity of palladium for hydrogen gas is due to its strong physical attraction to the gas molecules and the ability of hydrogen to easily penetrate its surface and form bonds with the metal atoms. The release of heat during this process is a result of the formation of pd-h bonds.