how does platinum splits hydrogen into hydrogen ions and electron?

[Jerryt12]

thanks

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as occur in a fuel cell

[Jerryt12]

In a hydrogen fuel-cell, hydrogens are passing through a platinum catalyst. As it go through, it's split into hydrogen ions and electron. So how does the platinum catalyst does that? What are the science behind it.

[whitepage]

Did you get an answer and it was deleted? I would love to know

[Vasanth M S]

Well actually, when water ( H2O ) undergoes electrolysis they get split into OH- ions and H+. Now at cathode ( Cathode is the negatively charged platinum electrode ) : H+ will gain one electron and will become H. Now this H again combines with another H and finally becomes H2 molecule. At anode ( Anode is the positively charged platinum electrode ) : The OH- ion will lose one electron. Thus 4OH will give 2 molecules of H2O and one molecule of O2. For better understanding look at the following equation below.

 

At cathode :

H⁺ + e^- --> H

H + H --> H₂

 

At cathode :

OH^- --> OH + e^-

4OH --> 2H₂O + O₂

 

Complete equation :

2H₂O --(electrolysis)--> 2H₂ + O₂

 

I hope this helped you.

[Enthalpy]

There are no free protons in a fuel cell. They're dissolved, for instance in water, or absorbed in a polymer membrane.

[whitepage]

my understanding of the process of the proton exchange membrane fuel cell was that the input is H2 and is ionized catalytically at the anode by means of the platinum. this leaves H+ ions, which travel through the polymer membrane, and e- which are forced to travel along an external circuit, producing the power output. from there the H+ are supposed have crossed the cathode, which continues to confuse me, and combine with incoming O2 and the e- of the finished circuit, resulting in H2O. how does the platinum have this effect and what makes it more suited to this function than other elements or compounds. as a bonus question, why do the protons cross the cathode instead of being attracted to it?

[Strange]

 

how does the platinum have this effect and what makes it more suited to this function than other elements or compounds.

 

I think this is because the hydrogen and oxygen molecules are "adsorbed" onto the surface of platinum. This changes the bonding energy of the molecules and brings them closer together thus making the reaction easier (more energetically favourable). I'm not sure that the detailed physical processes involved are that well understood. (Well, not by me, anyway!)

[mississippichem]

 

I think this is because the hydrogen and oxygen molecules are "adsorbed" onto the surface of platinum. This changes the bonding energy of the molecules and brings them closer together thus making the reaction easier (more energetically favourable). I'm not sure that the detailed physical processes involved are that well understood. (Well, not by me, anyway!)

There have been DFT models made of simple diatomics and small molecules being adsorbed onto a metal surface. It has to do with overlap of the molecule's HOMO and the metal's conduction band IIRC.

 

Other than that I know very little about the topic. Surface chemistry is incredibly incomprehensible to me for some reason. I have no intuition for it and the useful calculations are quite high level.