EO 11110?
My links go to his two Annual Economic Reports. The EO you linked to is part of his same policy of doing away with silver certificates.
The odd part is that in his reports to Congress he advocates using the Treasury silver thereby “freed up” for silver coinage. But the act of ceasing silver certs had the natural consequence of doing away with silver coinage, otherwise you end up with one of those arbitrage situations between currency and coins.