I don't think so because with the self-paced ("Days to Complete") option, Catalog creates a new section with each enrollment. So even if you added a section, Catalog would create new ones. If you're not using the Days to Complete option in the Catalog listing settings, you still can't add a section, you can only change which section to which the listing is enrolling. If you wanted to do that, you would add the section to the course in Canvas, in the Settings area, and then select this section for your existing Catalog listing. Also, keep in mind that Catalog will not allow you to list the same course twice, so you could not list 2 sections separately. You may need to just copy the course and set up a new listing.