If anything, economic troubles reinforce the determination.
Once people take independence as a question of pride, they're extremelly reluctant of considering selling their independence for money.
Anyway, I think the calculus is unique in this case. We are already seeing major companies move their headquarters out of Catalonia. Catalonia's independence would mean disruption of access to EU common market benefits and Schengen. Also they couldn't stop smaller provinces from voting to rejoin Spain.
Not sufficient to win maybe, but definitely to mandate some sort of peacekeepers.