Exhibit 31.2

CERTIFICATION OF CHIEF EXECUTIVE OFFICER PURSUANT TO RULE 13a-14(a)/15d-14(a)
 
I, Douglas J. Swirsky, certify that:
 
1. I have reviewed this annual report on Form 10-K of Rexahn Pharmaceuticals, Inc.;
 
2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;
 
Date: April 29, 2020
 
By: 
/s/ Douglas J. Swirsky
 
 
Douglas J. Swirsky
 
Chief Executive Officer and President