@ItsLarry service catalog URL is fixed, I believed you are looking for the RITM or sc_request URL attached to some incident. Since you want the button on list view and req/ritm gets attached to particular incident, what you are looking for might not be feasible.

Hi Larry,
This can be done by defining a "Declarative Action".
Steps:
Go to Left Nav and type "Declarative Action" and select "Create New Action".

Select "List" as you want this action to be on List View.

Put in the action name and
select "Client Script" in Implemented as field
View as "Service Operations Workspace"
Table as "sc_req_item"
and add the client script referring to the URL to open a Service Catalog Window on SOW.

UI Action on SOW List view of Requested Items:

Clicking the UI action redirects to Service Catalog page within the Workspace.