Electrochemical carbon corrosion occurring in a high temperature proton exchange membrane fuel cell (HT-PEMFC) operating under non-humidification conditions was investigated by measuring CO2 generation using on-line mass spectrometry and comparing the results with a low-temperature proton exchange membrane fuel cell (LT-PEMFC) operated under fully humidified conditions. The experimental results showed that more CO2 was measured for the HT-PEMFC, indicating that more electrochemical carbon corrosion occurs in HT-PEMFCs. This observation is attributed to the enhanced kinetics of electrochemical carbon corrosion due to the elevated operating temperature in HT-PEMFCs. Additionally, electrochemical carbon corrosion in HT-PEMFCs showed a strong dependence on water content. Therefore, it is critical to remove the water content in the supply gases to reduce electrochemical carbon corrosion. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.