Before an object could be converted to energy (which would be an enormous amount of energy, E=mc2) you would need an atomic map of the object.
IMO, being able to get an atomic map of an object, and being able to build objects at the atomic level, would be one of the most valuable thing the human race could ever learn.

With such technology, space explorers could get to their destination and build whatever they need.
Instead of converting matter into energy teleporting that energy, and converting it back to matter, the atomic map could be send to the destination world, and the ‘teleportation’ device could use the matter there to build the object- after all an oxygen atom here on Earth is the same as one on Mars.
Taking this a step forward, instead of trying to teleport a person to another world, we could send their atomic map and build a copy of them. Going even further, we could use such technology to teleport a whole biosphere to an Earth-like planet around another star. This may be a way for the human race to spread out to the stars.