Travailing to China with US Passport

I carry US Passport and I am travailing from Saudi Arabia to Manila and would like to stop by to visit my vendor in Xuzhou for three days.
My ticket is Saudi to Manila -
Manila to Shanghai -
Shanghai - Manila,
Manila - Saudi Arabia.

Can I apply for the 144 hours at Shanghai Airport?
I am travailing on Monday to Manila and don't have time to apply at the Embassy.

Regards,