The present invention disclosed herein is directed to nitric acid regeneration fuel cell systems (110) that comprise: an anode (112); a cathode (114) confronting and spaced apart from the anode; an anolyte flowstream (116) configured to flowingly contact the anode, wherein the anolyte flowstream includes a fuel, preferably methanol, for reacting at the anode; a catholyte flowstream (118) configured to flowingly contact the cathode, wherein the catholyte flowstream includes nitric acid for reacting at the cathode to thereby yield cathode reaction products that include nitric oxide and water in a catholyte effluent flowstream (120); and a hydrogen peroxide flowstream (122) configured to contact and react hydrogen peroxide with the nitric oxide of the catholyte effluent flowstream at a hydrogen peroxide oxidation zone (124) to thereby yield a regenerated nitric acid flowstream (126). The regenerated nitric acid flowstream is preferably reused in the catholyte flowstream.
