Originally Posted by henrus

"A foreign citizen who is transiting through China by air is exempted from a visa if he/she will stay only inside the airport (without entering the boder control) for no more than 24 hours and has a valid connecting ticket with confirmed seating on an international flight."

Visa-free Entry into Mainland China

Introduction to Chinese Visa ? Embassy of the People's Republic of China in the United States of America (here is the same info on the USA Chinese Embassy website with a list of countries)

So for the OP assuming he can get a boarding pass from a transit desk, mobile boarding pass or get one at the point of origin then no visa is required. Those details are from the Chineses embassy in Australia but I'd guess for most it would be the same. I'd suggest just double checking prior to travel (with your countries Chinese embassy) and having printed copies of the details stating no visa and also your airline tickets.