[kfilippi]

Hello everyone,
Can, in atmospheric pressure but in high temperature, graphite react with hydrogen?
We are thinking in the lab to use some Argon gas with 2.4% of H2, for some high temperature (over 1000 Celsius degrees) measurements on graphitic materials. The problem is that there are some oxidation issues during these measurements, even if we use pure argon, and H2 is known as an oxidation reducing gas, used for brazing techniques for example. My concern is that methane or some other Hydrocarbon can be produced using the H2 gas.

I would appreciate if someone can suggest a paper with some kinetics that I can do some calculations.

Thanks a lot in advance.

[rolnor]

What reaction do you want to have? Methane or other hydrocarbon seems like the most expected product if graphite reacts with hydrogen?

[Enthalpy]

Graphite reacts rather quickly in hydrogen at 3000K. At 1000°C, I don't know. With luck, it's slower than graphite with oxygen, which is very slow at 1000°C. You might ask a graphite manufacturer, as this information is rather banal.

If you suspect traces of oxygen in the argon, why shouldn't you let a solid scrub it, rather than hydrogen? A hot metal powder would do that and leave no gaseous products. Something like hot iron powder.

Depending on grain size, metal powders can be dangerous too.

In case the oxidizing impurity in argon is water vapour rather than oxygen, a metal will scrub it too, while hydrogen doesn't. And even if the oxidizing impurity is oxygen, the water produced by hydrogen reaction may react with graphite.

[Corribus]

Hydrogenation of conjugated hydrocarbons, e.g., pyrene, usually requires a catalyst like finely granulated nickel (Raney nickel) and are carried out at pretty high pressures in something like a Parr vessel. These reactions are usually reasonably efficient under these conditions but dangerous if you don't know what you're doing.

Maybe graphene would react similarly?

Ultimately it depends on what you mean by "can". Many reactions "can" happen, and even do, but are very slow, sometimes too slow to be observed. So you should distinguish whether you mean "can" or "can on a practically relevant timescale".