Performance degradation of a direct methanol fuel cell by an eluted plasticizer

► Power degradation occurred in a direct methanol fuel cell (DMFC) with a plastic tube was investigated. ► Di-(2-ethylhexyl) phthalate (DEHP), a plasticizer, was detected in the circulated methanol solution. ► The degradation in performance by DEHP was confirmed. ► DEHP would affect the methanol transport through the PCP.