The options I can think of would be:
The propane might react with the hydrogen (producing perhaps ethane and/or methane)
The hydrogen might dissolve in the propane.
My personal opinion is that neither of these is likely.
The bonding strengths of both propane and hydrogen are high enough, relative to the energy released in the reaction, to make any reaction between them unfeasibly slow
(at room temperature without a catalyst).
My personal gut feeling is also that the inter-molecular attraction between hydrogen and propane would be low, making any significant dissolving unlikely.