Outlook for Mac doesn't use .pst files - the equivalent on Mac is .olm
The profile is located here for Office 2016 (the "~" in the path is the home directory of the user):
~/Library/Group Containers/UBF8T346G9.Office/Outlook/Outlook 15 Profiles/Main Profile
<http://www.officeformachelp.com/2015/04/location-of-outlook-2016-profile-identity/>