Unfortunately you cannot extend the CatalogNode in EPiServer Commerce and when browsing to it, you get a 404 page. Hopefully this will be possible in a future version.
In the meantime you can use this to display your catalog node:
public class CatalogContentController : ContentController<CatalogContent> { public ActionResult Index(CatalogContent currentPage) { return this.View(currentPage); } }
In your view you can render a partial view, some static html, etc.
You could also use a ViewModel in which you can implement some logic to display the things you want.