고분자전해질 연료전지 (PEMFC) 장기 사용과정에서 스택요소의 부식 및 공급 가스의 오염에 의해 막전극 합체 (MEA)의 화학적 열화가 발생한다. 본 연구에서는 화학적으로 열화된 MEA를 산 세척해서 성능을 회복시킬 수 있는지 연구하였다. 철 이온을 오염시키고 황산 수용액으로 세척하여 PEMFC 셀에서 성능을 측정해 비교했다. 0.5 ppm의 철 이온오염에 의해 약 25%의 성능 감소가 있었고 0.15 M 황산 세척에 의해 97.1% 성능회복이 가능했다. 고분자 막의 철 이온 오염에 의해 막 저항이 증가했고, 저농도 황산 수용액 세척에 의해 전극 촉매의 손실을 최소화하면서 막에서 철 이온을 세척함으로써 이온전도도가 회복되었다. PEMFC MEA의 화학적 오염에 의한 내구성 감소를 산 세척에 의해 해결할 수 있는 가능성을 확인하였다.

In the process of long-term use of PEMFC (Proton Exchange Membrane Fuel Cells), chemical degradation of membrane electrode assembly (MEA) occurs due to corrosion of stack elements and contamination of supply gas. In this study, we investigated whether chemically degraded MEA can be recovered by acid washing. The performance was measured and compared in a PEMFC cell after contamination with iron ions and washing with an aqueous sulfuric acid solution. The performance was reduced by about 25% by 0.5 ppm iron ion contamination, and 97.1% performance recovery was possible by washing of 0.15 M sulfuric acid. The membrane resistance was increased due to iron ion contamination of the polymer membrane, and the ionic conductivity was restored by washing the iron ions from the membrane while minimizing the loss of the electrode catalyst by washing with a low-concentration sulfuric acid aqueous solution. The possibility of solving the decrease in durability caused by chemical contamination of PEMFC MEA by the acid washing was confirmed.

PEMFC Contamination Iron ion Acid washing Ion conductivity

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