Am I eligible?Husband and I are US passport holders.

Looking at booking round trip flight Bangkok to Beijing (Thai Airways) landing 0530. Then round trip flight Beijing to the US (United) departing 1425 of the same day. Will we qualify for the transit free visa because we are doing two separate bookings? Not sure if we have to fly a certain airline or we have to just book Bangkok to US. Just don’t want to be denied.