The article title is misleading.
An oxygen powered jet did not travel the world in 4 hours.
An oxygen powered jet did not travel at all.
An oxygen powered jet does not exist.
But someday, using this new engine technology, it might be possible.
But someday, using this new engine technology, it might be possible.
But without an oxidizer combustion is not possible. I don't know of any airplane (jet or propeller) that uses anything but oxygen as it's oxidizer.