Service and Category data is stored separately, although there are only two places where this data is stored. The only way for this to occur would be to write a cutover script that essentially copies over all of the Service Catalog data from the test environment to the production environment.
In short, there is currently no way to automate this process. A technician at your organization would have to create a script that manually transfers this data over from one database environment to the other, as you are installed.
Otherwise, you would need to manually re-create the Service Catalog in the production environment. I hope this helps to explain how service catalog data can be transferred from a sandbox to production. Please let us know if you would like further clarification or there is anything else we can do to help you.