Stopping enroute to the US from Manila, Philippines

I will be having around a 9 hour layover in Shanghai on my flight from Manila to the US. I am a US Citizen with a valid passport and will be leaving out of the same airport (Pudong Airport). Am I allowed to use the Free Transit Visa when I arrive in Shanghai? Also, would I be allowed to go to down town Shanghai and look around/sightsee for a few hours?