Electrochemical redox methods and systems for implementing for continuous removal of hydrogen sulfide and other sulfur species from sour gas mixtures using transitional metal oxide, sulfide, or carbonate compounds which are regenerated. In one embodiment, in the overall reaction hydrogen sulfide is converted into hydrogen and sulfur: H2S(g) = H2(g) + S(s); applied ^E = 0.20 ~ 0.50 V The columbic efficiency of both methods generally exceeds 90%
