【摘要】：貴金屬Pt由于其較高的催化活性、良好的耐腐蝕、抗氧化與穩(wěn)定性等使得其在各行各業(yè)中得到應(yīng)用,但由于Pt的價(jià)格比較昂貴使得成本提升,為此如何在確保催化性能不降低的情況下有效降低Pt的用量來降低成本成為研究的熱點(diǎn)。當(dāng)前主要是在Pt催化劑的基礎(chǔ)上添加賤金屬元素,以此來形成新型的Pt基催化劑。本文主要通過離子束濺射技術(shù)(IBS)制備一定沉積溫度下的PtCu/C梯度催化劑薄膜,以此來探究沉積溫度對(duì)雙金屬催化劑催化性能的影響。通過電化學(xué)循環(huán)伏安法(CV)和線性掃描伏安法(LSV)對(duì)催化劑薄膜性能進(jìn)行表征;采用電感耦合等離子體發(fā)射光譜(IPC-AES)、X射線衍射(XRD)、高分辨透射電鏡(HR-TEM)對(duì)催化劑樣品的成分、物相、表面形貌進(jìn)行表征;采用場(chǎng)發(fā)射掃描電鏡(FESEM)對(duì)催化劑顆粒在Nafion膜表面孔道形態(tài)進(jìn)行表征;通過苯加氫裝置對(duì)PtCu/C/Nafion復(fù)合催化劑加氫性能進(jìn)行測(cè)試。結(jié)果表明:(1)電化學(xué)性能隨沉積溫度呈現(xiàn)先增后減的特征,即隨著沉積溫度的升高,電化學(xué)性能先增強(qiáng),當(dāng)沉積溫度達(dá)到250℃后,隨沉積溫度的繼續(xù)升高,性能反而下降。與常溫條件下制備的C和C1樣品相比,腐蝕前的最大增長(zhǎng)率為18.03%,腐蝕處理改性后的最大增長(zhǎng)率為33.63%。,通過Z4和ZS4與常溫純Pt/C相比,其i0值分別增長(zhǎng)10.1%和64.7%(常溫Pt/C的i0值為0.003 901 A/cm2),具有較高的實(shí)用性。275℃沉積溫度經(jīng)過后處理改性的性能與250℃的性能相接近,因此對(duì)于梯度雙金屬PtCu催化劑薄膜適宜的沉積溫度為250～275 ℃。(2)采用三次超聲波震蕩分散處理和超聲自然沉積的方式,能夠使催化劑顆粒的整體分布隨著液面高度逐漸下降,顆粒均勻化程度逐漸增加,且形成結(jié)構(gòu)緊湊,催化劑顆粒大小均一,分布均勻的PtCu/C/Nafion膜電極結(jié)構(gòu)。(3)通過在-0.3V電解電壓下的苯加氫測(cè)試表明,與常溫條件下的純Pt樣相比,250℃沉積溫度下的純Pt樣和雙金屬梯度PtCu樣,其加氫效率分別提升了 62.32%和63.86%;PtCu梯度膜電極的加氫性能對(duì)比表明250℃制備的較常溫制備的提升17.56%,而250℃制備的PtCu梯度膜電極經(jīng)后處理改性僅提升3.92%,說明沉積溫度對(duì)膜電極苯加氫效率的影響要強(qiáng)于后處理改性過程。
[Abstract]:Precious metal Pt has been applied in various industries because of its high catalytic activity, good corrosion resistance, oxidation resistance and stability, but because of the high price of Pt, how to effectively reduce the amount of Pt to reduce the cost has become the focus of research. At present, a new type of Pt based catalyst is formed by adding base metal elements to Pt catalyst. In this paper, the effect of deposition temperature on the catalytic performance of bimetallic catalysts was investigated by preparing PtCu/C gradient catalyst thin films at a certain deposition temperature by ion beam sputtering (IBS). The properties of the catalyst thin films were characterized by electrochemical cyclic Voltammetric method (CV) and linear scanning Voltammetric method (LSV), the composition, phase and surface morphology of the catalyst samples were characterized by inductively coupled plasma emission spectroscopy (IPC-AES) and X-ray diffraction (XRD), high resolution transmission electron microscope (HR-TEM), and the pore morphology of the catalyst particles on the surface of Nafion film was characterized by field emission scanning electron microscope (FESEM). The hydrogenation performance of PtCu/C/Nafion composite catalyst was tested by benzene hydrogenation unit. The results show that: (1) the electrochemical performance increases at first and then decreases with the deposition temperature, that is, with the increase of deposition temperature, the electrochemical performance increases first, and when the deposition temperature reaches 250 鈩，

本文編號(hào)：2503890