Temp Entry Permit, 72 hours visa free transit?? Thai and US Passports, visit Beijing less 48 hours

HI, I am travelling with my family from Bangkok to USA. It is 12 hours layover in Beijing. We are thinking of getting out of the airport and book hotel for a night or small sightseeing. I am holding Thai passport and my husband and kids have US passport. Can we apply for temporary entry permit to enter China and back in airport to board the flight to USA? Do we need to apply in advance or we can do it directly at Beijing airport? Thank you very much.