Do I need a Visa for less than 24 hour transit through China (PVG)?

Hello. I am a US citizen with a US passport. I arrive in PVG Sunday night 2/12/12 7:45PM from Los Angeles. No flight is available to my final destination of HKG until 4:40PM the next day, 2/13/12. Can I stay in a hotel in the city for the night, then return to the PVG airport on 2/13/12 for my 4:40PM flight without having to purchase a Visa? thanks