Hello Tennighenn13
Yes, this is possible. It will cost CHF 26.50 per person, one way. You can get it online, at the SBB Travel Center at Geneva station, or on the train with the conductor (on IR and IC trains, you can purchase class upgrades with the conductor yet no other tickets).
Using the Swiss Travel Pass, you can upgrade it for the half of the difference of the cost for a point-to-point ticket in 2nd vs. a 1st class ticket. You could also upgrade if for a day.
Kind regards,
Roland