144 Hour Free Transit Visa work for both for layovers too and from my destination?

I am a US citizen traveling through PEK on my way to S Korea. I am planning on staying one night in PEK on my way to INC, and one night in PEK on my way back to the US two weeks later. Will I need a visa for that, or will I be covered under the 144 Hour Free Transit Visa, even though its over two layovers?