Italy - Beijing - Vienna/Austria (stop flight) - Italy

Your itinerary is definitely eligible for 144 hour visa free transit under the condition that those are your all stops, especially within mainland China. Europe - China - Europe is perfectly eligible for visa free transit in case if you have two different European countries as immediate points before and after your Chinese destination as is in your case. You have Italy and Austria as two immediate points and consequently, your itinerary is eligible.

By the way, this is not 144h free transit visa, but 144 hour visa free transit or in other words, there is no visa at all.

Thank you so much! Is it the same for the 72h visa free transit?

Yes, exactly the same thing is valid for 72 hour visa free transit, but this option has remained actual in just five Chinese cities: Chongqing, Harbin, Xi'an, Guilin and Changsha. In reality, we should expect that even these cities will have its 72 hour extended to 144 within a couple of years.