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휴대용 고분자전해질 연료전지의 수소발생용으로써 NaBH4는 많은 장점을 갖고 있다. 본 연구에서는 고농도 NaBH4용액에서 비담지 Co-P-B, Co-B 촉매의 NaBH4 가수분해 특성에 대해 연구하였다. 고농도에서 수소 발생 수율을 높이기 위해 NaBH4 가수분해 반응의 수소 발생 수율에 미치는 촉매 형태, NaBH4 농도, 응축수 회수 등의 영향에 대해 실험하였다. Co-P-B 제조과정에서 붕소의 비가 높아질수록 수소 발생 수율이 증가하였다. Co-P:B = 1:5 촉매를 사용해 NaBH4 수용액 농도를 20 wt%에서 25 wt%로 증가시켰을 때 수소 발생 수율이 감소하였다. Co-P-B와 Co-B 촉매를 같이 사용한 반응기에서 촉매 팩의 두께를 감소시키고 응축수를 회수하여, NaBH4 25 wt% 수용액으로 최고 수소 발생수율 96.4%를 얻었다.

− Recently, there are many efforts focused on development of more economical non-fluorinated membranes for PEMFCs (Proton Exchange Membrane Fuel Cells). In this study, to test the durability of sPEEK MEA (Membrane and Electrode Assembly), ADT (Accelerated Degradation Test) of MEA degradation was done at the condition that membrane and electrode were degraded simultaneously. Before and after degradation, I-V polarization curve, hydrogen crossover, electrochemical surface area, membrane resistance and charge transfer resistance were measured. Although the permeability of hydrogen through sPEEK membrane was low, sPEEK membrane was weaker to radical evolved at low humidity and OCV condition than fluorinated membrane such as Nafion. Performance after MEA degradation for 144 hours and 271 hours were reduced by 15% and 65%, respectively. It was showed that the main cause of rapid decrease of performance after 144 hours was shorting due to Pt/C particles in the pinholes.

최근에 저가의 고분자 전해질 연료전지(Proton Exchange Membrane Fuel Cells, PEMFC)용 비불소계 전해질 막 연구개발이 활발히 진행되고 있다. 본 연구에서는 sulfonated Poly(ether ether ketone)(sPEEK)막의 특성을 술폰화도, 상대습도, 단위 전지 온도에 따라 PEMFC 운전 조건에서 비교하였다. I-V 분극곡선, 수소투과도, 전기화학적 표면적, 막 저항 및 부하 전달 저항 등을 측정·분석했다. 술폰화도와 온도, 상대습도가 높을수록 성능이 높았으며, 특히 낮은 슬폰화도와 낮은 상대습도에서 이온 전도도 감소 때문에 성능이 큰 폭으로 감소함을 확인하였다.Abstract − Recently, there are many efforts focused on development of more economical non-fluorinated membranesfor use in PEMFCs (Proton Exchange Membrane Fuel Cells). In this study, characteristics of sulfonated Poly(ether etherketone) (sPEEK) were compared according to degrees of sulfonation (DS), relative humidity, cell temperatures at PEMFCoperation condition. I-V polarization curve, hydrogen crossover, electrochemical surface area, membrane resistance andcharge transfer resistance were measured. sPEEK membrane showed high performance at high DS, high temperatureand high relative humidity, in particular, performance of sPEEK membrane decreased largely due to low ionic conduc-tivity at low DS and low relative humidity.Key words: PEMFC, sPEEK, Performance, Degrees of sulfonation, Relative Humidity, Cell Temperatures, Ionic Conductivity

Anode는 효소를 이용한 효소전극과 cathode는 PEMFC용 전극을 이용해 효소연료전지를 구동하였다. 효소 anode는graphite 분말과 효소로서 글루코스 산화제, 전자매개체로 ferrocene을 혼합해 압축해서 만들고 Nafion 이오노머로 코팅하였다. Anode 제조조건을 변화시키며 성능을 측정해 효소 anode 제조 최적조건을 찾았다. 효소 anode 압축 시 최적 압력은 8.89 MPa이고, 효소 anode의 graphite 성분비가 60%일 때 최고의 출력밀도를 나타냈다. Anode 기질 용액의 최적glucose 농도는 1.7mol/l이었다. 효소 anode는 Nafion 용액에 1초, 2회 침지에 의해 안정화되었다. Abstract − Enzyme fuel cells were operated with cells composed of enzyme anode and PEMFC cathode. Enzymeanodes was fabricated by compression of a mixture of graphite particle, glucose oxidase(Gox) as a enzyme and ferro-cene as a redox mediator, and then coated with Nafion ionomer solution. Performances of enzyme unit cell were mea-sured with variation of anode manufacture factors, to find optimum condition of enzyme anode. Optimum pressure was8.89MPa for enzyme anode pressing process. Highest power density was obtained at 60% graphite composition inenzyme anode. Optimum glucose concentration was 1.7 mol/l in anode substrate solution. The enzyme anode was sta-bilized by two times of deeping in Nafion solution for 1 sec.Key words: Enzyme fuel cells, Performance, Pressing Anode, Fabrication method, Glucose oxidase, Stability