Q: Can I buy a T10 ticket at the RENFE train station at T1 ?
A: No. There is no RENFE train stop at Terminal 1 at Barcelona Airport (El Prat de Llobregat). You would need to transfer from Terminal 1 to Terminal 2B using the free airport shuttle bus. You would then be able to buy the T10 ticket from the RENFE train stop at Terminal 2.
There is a Metro link at Terminal T1 and Terminal T2 however the T10 ticket is not valid on the metro link. If you wanted to buy a ticket for the metro from Barcelona airport it would cost you €4.50 . See our page on taking the metro from Barcelona airport to the city centre.
The following links will help you plan your journey