It was

Binance in talks with FC Barcelona over sponsorship

FC Barcelona Releases Its Cryptocurrency - Medium

It was, but Barcelona decided in the end not to go with anybody in the crypto space.

Polkadot In Race To Become FC Barcelona’s Official

Was Polkadot really in the race to become one of Barca's sponsors?

Polkadot Could Become FC Barcelona’s Official Jersey

A few weeks ago

Polkadot could be Barcelona's new master sponsor

FC Barcelona Chooses Spotify Over Crypto Sponsors

A few weeks ago, the news also emerged that Binance and FTX were also vying for the main space on the Barcelona shirt, but apparently, the negotiations have not