本研究使用脈衝雷射沉積法(Pulsed Laser Deposition, PLD)製備Pt/Co (25/75 at %, PtCo3)奈米顆粒並應用於燃料電池陰極端之觸媒層。PtCo3於總擔量100 μg/cm2時，其質量比功率密度(Mass Specific Power Density, MSPD)在0.6 V下僅有3.5 kW/gPt，是因為大約減量了50%的白金擔載量。 而後結合了連續雷射退火(Continuous Wave Laser Processing, CWLP) 以有效提升Pt使用率及耐久性。本研究經過CWLP於2.4 W 0.35 mm/s條件下，可以有效增加奈米顆粒觸媒層的Pt反應表面積進而提升電池之性能，其MSPD於0.6 V下可以達到8.79 kW/gPt，比起沒有結合CWLP之電池整整提升了2.5倍之多；合金觸媒可以在降低Pt擔載量的同時，仍然保有優良的觸媒活性，推論是因為由PLD建立的觸媒微結構比起傳統的塗佈製程更能夠建立有效的三相點，再加上CWLP可以使觸媒表面重新排列形成Pt殼層，提高觸媒利用率進而得到高MSPD。 有結合CWLP之觸媒在經過5000圈加速老化循環測試後仍保有50%以上的化學活性表面積，此結果顯示使用CWLP進行熱處理可以於奈米觸媒製造出具有Pt殼層的PtCo3合金觸媒，同時也會有燒結作用，增強顆粒間之鍵結，以提升觸媒耐久性，具良好的化學穩定性。 結合PLD及CWLP製程所製備之PtCo3奈米顆粒觸媒層，可有效降低燃料電池中Pt擔載量並保有優良的觸媒活性，提高觸媒使用率。進而提升燃料電池性及耐久性並降低燃料電池成本，使燃料電池更加普及進而永續環境。 ;The catalyst layers for polymer-electrolyte-membrane fuel cells (PEMFC) are fabricated by deposition of platinum directly onto the gas diffusion layer using pulsed laser deposition (PLD). This technique reduces the number of steps required to synthesize the catalyst layer and the required Pt loading for PEMFC. In this study, PLD is used to reduce the Pt loading and the cost of the cell. A thin film of PtCo3 nanoparticles was deposited on gas diffusion layer by PLD process and further subjecting the film to scanning continuous-wave laser processing (CWLP). In CWLP, the Pt skin forms over the surface of PtCo3 nanoparticles via Pt segregation with enhanced firm contact between nanoparticles. Thereby increasing electrochemical surface area with concomitant sintering effecting. The Pt skin formation could retain the stability and performance of catalyst with decrease in Pt loading. Application of such catalyst to the cathode of a PEMFC exhibits a 2.5-fold increase in mass-specific power density (MSPD) with respect to that without laser processing, raising the cathode MSPD to 8.79 kW gPt−1 with 1 atm oxygen and 12.02 kW gPt−1 with 1.5 atm oxygen. Further increase in Pt-mass-specific power density might be achieved by reducing the Pt content in the starting Pt alloy and changing the ambient gas pressure in pulsed laser deposition to optimize the initial particle size.
