This may seem like a basic question to educated chemists, but I failed to get this answer on Internet searches. I keep getting more complicated stuff like the Haber process which is not relevant.
At this website it describes how the absorption cooling process works in a propane powered refrigerator. The system uses ammonia, water, and hydrogen in closed loop system. In the evaporator section, it says liquid ammonia reacts with hydrogen gas thus vaporizing it and this process of ammonia boiling in hydrogen absorbs heat from the fridge box. It doesn't mention what the end products of the ammonia and hydrogen reaction are.
Is there a chemical reaction between hydrogen and ammonia here? Or is there no actual chemical reaction, just partial pressure vaporization of ammonia liquid in hydrogen gas?