You can save a catalog under a different name, which essentially creates a copy of it.
To create a copy of a catalog under a different name:
Select File > Catalogs > Catalog Manager, or right-click an element in the catalog panel and select Catalog Manager.
Make sure the catalog you want to save is the current catalog.
Select File > Save Catalog As.
In the File name edit box, type the name you want to save under (without extension).
Click Save.
Note: The newly saved catalog becomes the current catalog.