The effect of addition of molybdenum in Fe-Cr-Mn based alloy on the chromium deposition and poisoning of LSM cathodes is investigated at 800 degrees C by electrochemical impedance spectroscopy and microstructure analysis. The Fe-Cr-Mn-Mo ferrite stainless steel metallic interconnect shows much less Cr deposition and poisoning on the LSM cathodes as compared with the Fe-Cr-Mn alloy. The addition of Mo into the alloy suppressed Cr evaporation from interconnects, decreased the degradation of cathode performance caused by Cr. According to SEM results, MoO3 and MnMoO4 is observed at the depositional area. The segregated MnO from LSM cathode can act as a nuclei agent, and react with vaporized Mo to form Mo-contained oxide particles, which will not inhibit the oxygen reduction reactions in the three phase boundary (TPB). As a result, suitable addition of Mo into the interconnect alloy can effectively alleviate the Cr poisoning of the LSM cathode. (C) 2016 Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC.