Any chemicals combines readily oxygen?
If $\ce{CO2}$ is acceptable in the feed gas, along with $\ce{CO}$ and a bit of left-over oxygen, then carbon (coal, charcoal etc.) might do. It's ignition temperature is ~1,000 K.

Magnesium is more expensive, but leaves less oxygen and has no gaseous byproduct. It's self-ignition temperature is ~800 K.

Many other materials could be used; it really depends on how the gas is to be used.