You can’t largely. At least not with offshore yuan. To do that you have to go through the controlled settlement channels to get onshore yuan. That’s tightly controlled to protect the peg.
So no one is going to use a controlled currency for a hard liquid commodity. So if China wants petro yuan they have to liberalize that, which will break their peg.
China could have more international trade in the yuan before all of Americas recent misadventures. But that has cast consequences for their economy, and possibly the ruling elites power structures.
Saudi Arabia was literally negotiating with China for payments in yuan for petroleum way before the war started, in 2023. The Gulf countries' largest trading partner is China - such a transaction is effectively a barter enabling programme. Russia and now Iran already accept yuan.
The mainland vs offshore renminbi restrictions disappear in Hong Kong, Singapore, etc. where most mainland Chinese trading companies and otherwise have offices anyways. Trading offshore to onshore renminbi becomes their problem, one that they are fairly accustomed to.
Very interesting, 2 different yuan’s!
Do you have more details on this? A book, a blog, an article?