【摘要】 分别采用乙醇-异丙醇、H2和NaBH4还原方法制备了凹凸棒土负载铂催化剂(分别标记为Pt/PAL(I)、Pt/PAL(II)和Pt/PAL(III)),其在对氯硝基苯(p-CNB)的催化选择加氢反应中表现出不同的催化性能.在Pt/PAL(II)催化剂上,对氯苯胺(p-CAN)的选择性达到了100%,并且在p-CNB完全转化的情况下,脱氯反应得到了完全的抑制.在Pt/PAL(I)和Pt/PAL(III)催化剂上,尽管脱氯反应没有得到完全的抑制,但也分别得到99.7%和99.9%的p-CAN选择性.Pt/PAL(I)催化剂表现出最高的催化活性,转化频率(TOF)值高达27010h-1.Pt/PAL(II)和Pt/PAL(III)催化剂表现出稍微低的催化活性,TOF值分别为17193和24871h-1.利用透射电镜(TEM)、X射线衍射(XRD)和傅里叶变换红外光谱(FTIR)对催化剂样品进行了表征,结果表明优异的催化性能主要归因于铂粒子尺寸和凹凸棒土载体的影响.更多还原

【Abstract】 The palygorskite supported platinum catalysts, Pt/PAL(I), Pt/PAL(II), and Pt/PAL(III) were prepared by different reduction methods (ethanol-isopropanol, H2, and NaBH4), and exhibited different catalytic properties for the hydrogenation of para-chloronitrobenzene (p-CNB). Over the Pt/PAL(II) catalyst the selectivity of para-chloroaniline (p-CAN) reached 100% and the hydrodechlorination reaction was fully suppressed during the complete conversion of p-CNB. Superior selectivities of 99.7% and 99.9% for p-CAN were also obtained over Pt/PAL(I) and Pt/PAL(III) catalysts, respectively, although the dehalogenation reaction was not completely avoided. Pt/PAL(I) was the most active catalyst with a turnover frequency (TOF) of up to 27010 h-1. Pt/PAL(II) and Pt/PAL(III) catalysts showed slightly lower activity with a TOF of 17193 and 24871 h-1, respectively. These excellent catalytic properties are attributed to the effects of Pt particle size and the palygorskite support, which was confirmed by transmission electron microscopy (TEM) images and X-ray diffraction (XRD) patterns of the catalysts as well as Fourier transform infrared (FTIR) spectra of the palygorskite.更多还原