在燃料電池中，陰極觸媒的催化能力對於燃料電池的表現影響極大，本實驗成功的將錸摻雜於二硫化鉬中使晶體之結晶性降低以提升晶體對於氧氣還原反應之活性，首先，利用高溫爐管合成出摻雜不同錸金屬濃度之二硫化鉬，接下來，透過超音波震盪之方式，將摻雜錸金屬的二硫化鉬晶體剝離成較小尺寸，最後藉由高速離心取得不同尺寸的晶體，並對其進行觸媒活性之探討，在電化學分析的結果中顯示，利用X光繞射所分析出之結晶性與晶體在氧氣還原反應中的催化能力有相對應的關係，此外，為了增加觸媒具備之活性點位，本實驗提高離心轉速以收集尺寸較小之晶體，使本實驗可針對晶體尺寸對於氧氣還原活性之影響進行探討，從電化學分析的結果中可看出，隨著離心轉速的提升，觸媒對於氧氣還原反應的催化能力也隨之增強，並使氧氣還原反應之過程逐步接近四電子轉移，其中以錸摻雜濃度為50%並收集於離心轉速2000 rpm下之晶體，具備最高的催化活性，其最大之電流密度以及最高的電子轉移數出現在掃描電壓為-1.2 V時，分別為-5.24 mA cm-2以及3.91。

Catalytic activity of cathode catalyst has a great influence on fuel cell performance. In this research we have successfully controlled the doping concentration of rhenium to decrease the crystallization of rhenium-doped MoS2 (Mo1-xRexS2) and therefore increase the catalytic activity for oxygen reduction reaction (ORR). Mo1-xRexS2 was grown by furnace synthesized and followed by chemically exfoliated into smaller particle size using long term ultrasonication. Different size particles were separated and collected by high speed centrifugation. The electrochemical analysis shows that the crystallization of Mo1-xRexS2 defined by X-ray diffraction (XRD) had an obvious effect on ORR. Moreover, in order to increase the exposed active sites, we collected the Mo1-xRexS2 particles at high centrifugation speed to have a investigation of particle size effect on ORR activity. The catalytic activity of Mo0.5Re0.5S2 increased with the decrease of particle size and behaved nearly four-electron transfer toward ORR. The current density of Mo0.5Re0.5S2 collected at 2000 rpm can reach to -5.24 mA cm2 and has the electron transfer number (n value) of 3.91 at -1.2 V.

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