Will this route work?

Hi there, my brother-in-law plans to come to Shanghai next month for my and my husband's wedding celebration.
He has a British passport. He wants to fly from London to Shanghai (arriving Dec 5th), then from Shanghai to Vienna (direct, leaving Shanghai on Dec 10th). He wants to book his Vienna to London flight on a separate ticket.

Please could you advise if this qualifies for the 144 hour visa-free transit?
Thanks!1