qualify for a 72 hour visa free transit

My wife and I have a three day layover in Beijing. We will be leaving Seattle, Washington to Bali, Indonesia for 8 days. On our way back to Seattle we have a three day layover in Beijing. We arrive in Beijing Capital International Airport at 5:00 am on 2018-03-13. We depart from Beijing International Airport on 2018-03-16 at 12:19 pm. We are not clear if we need a tourist visa, or if we qualify for a 72 hour visa free transit. Can you please clarify.