US green card holder Indian passport and layover in Bejing. Eligible for 24 hour transit visa?

I am an Indian passport holder and US Permanent Resident (greencard holder) travelling via AirChina from Mumbai to Los Angeles and have a layover in Bejing for nine hours. Do I need G Visa to visit Bejing city or am I eligible for a 24 hour transit visa at the Bejing airport?
Nikhilesh Jhaveri