You will need a visa if you return to the same country on your return flight; i.e. DFW-PEK-DFW
China's 72-hour transit visa only works if you are returning via a 3d country: a return via Tokyo or Hong Kong or Seoul would qualify, even if it is only a connection stop to a U.S. destination. The rationale is that you are "transiting" PEK on your way to NRT/ICN/HKG (even though your stop there is very short).
Last edited by pfbloom; Jan 23, 2016 at 4:49 pm