Then the question becomes, what gases are capable of holding onto the planet surface? And how do we make them?

Why do we want gases to hold onto the planet? To maintain a temperature range that is non-deadly to human beings. 

What gases would these be? 

How do we make them? Do we use the analytical muscle of quantum computing to unlock the secrets of biology, and then use CRISPR to create the flora and fauna to support the creation of this biosphere?

Can we then use the same tools and create a food and nutrition cycle that will ensure that the gases and nutrients are cycled?

Would Water continue to exist? Would water survive on such a surface? 

Finally, could we alter humans or give humans breathing apparatus or breathing biomes for the lungs that can use the gases and help us perform the human body?