一种双光束红外光谱及其在气固相多相催化反应实时原位表征中的应用（英文）

发布时间：2018-06-18 09:24

本文选题：双光束原位红外光谱 + 气相分子振动光谱　；参考：《催化学报》2017年01期

【摘要】：单光束红外光谱技术(原位傅立叶透射变换红外、原位漫反射红外和衰减全反射红外光谱技术)虽然已经用于气固相多相催化反应的原位表征中,但这些光谱在真实反应条件下会受到气体分子振动光谱和加热条件下产生的发射光谱的严重影响,不能实时获得催化剂表面的真实信息.另外,由于在真实的气固相多相催化反应过程中,催化剂本底的信息会随着反应时间的延长而发生变化,因此单光束红外光谱技术在扣除本底信息方面存在误差.为了实现在反应条件下,实时、原位表征催化剂表面的状态,我们报道了一种双光束红外光谱表征技术.该技术包括双光束红外光谱系统及双光束红外反应池.其特征在于:实时双光束原位红外光谱系统由两台完全相同的红外光谱仪和双光束红外反应池组成.双光束红外反应池由完全相同的样品池和参考池连接而成,样品池和参考池处于同一水平线上分别对应于样品光谱仪和参考光谱仪,由计算机同步控制两台红外光谱仪,排除实时状态下的气体分子振动光谱干扰和加热条件下产生的发射光谱干扰.该技术可以对真实反应条件下的气固相多相催化反应进行实时原位表征.通过应用程序的关联可以实时、同步采集样品光束和背景光束谱图来得到催化剂表面物种随反应时间变化的真实信息.该技术克服了单光束红外光谱在原位多相催化反应表征方面的缺陷,使表征结果变得更加精确可靠.该技术还可以在变化的气相组分条件下,获得不同温度下、实时的催化剂表面活性中心、活性相和中间物种的信息.采用上述双光束红外光谱仪对丁烯在纳米HZSM-5催化剂上芳构化反应过程进行了实时、原位观测,首次在实际反应条件下,观察到了异丁烯在纳米HZSM-5沸石的表面Br?nsted酸中心上经历吸附、活化、聚合、环化等反应步骤生成芳烃的过程.
[Abstract]:Single beam infrared spectroscopy (in situ Fourier transform infrared spectroscopy, in situ diffuse reflectance infrared spectroscopy and attenuated total reflectance infrared spectroscopy) has been used in the in situ characterization of gas-solid phase multiphase reactions. However, these spectra will be seriously affected by the vibrational spectra of gas molecules and the emission spectra generated under heating conditions under the real reaction conditions, and the real information on the catalyst surface can not be obtained in real time. In addition, the information of catalyst background will change with the prolongation of reaction time in the process of real gas-solid phase heterogeneous catalytic reaction, so there is an error in deducting background information by single-beam infrared spectroscopy. In order to characterize the surface state of the catalyst in real time and in situ under the reaction conditions, we report a double beam infrared spectroscopy technique. The technique includes two beam infrared spectrum system and two beam infrared reaction cell. The characteristic of the system is that the real time dual beam in situ infrared spectroscopy system is composed of two identical infrared spectrometers and two beam infrared reaction cells. The double beam infrared reaction cell is connected by the identical sample pool and reference pool. The sample pool and the reference cell are respectively corresponding to the sample spectrometer and the reference spectrometer at the same horizontal level. The two infrared spectrometers are controlled synchronously by the computer. The vibration spectrum interference of gas molecules and the emission spectrum interference under heating condition are eliminated in real time state. This technique can be used for in situ characterization of gas-solid multiphase catalytic reactions under real reaction conditions. Through the correlation of the application program, the sample beam and the background beam spectrum can be collected synchronously to obtain the true information of the change of the surface species with the reaction time. This technique overcomes the defects of single beam infrared spectroscopy in the characterization of in situ multiphase catalytic reactions and makes the characterization results more accurate and reliable. The technology can also obtain real-time information on the surface active center, active phase and intermediate species of the catalyst at different temperatures under the condition of varying gas composition. The process of aromatization of butene on nanocrystalline HZSM-5 catalyst was observed in real time and in situ by using the dual-beam infrared spectrometer. The adsorption, activation, polymerization and cyclization of isobutene on the surface Brnsted acid of HZSM-5 zeolite were observed.
【作者单位】：大连理工大学化工与环境生命学部精细化工国家重点实验室;中国科学院大连化学物理研究所催化基础国家重点实验室;
【基金】：supported by the National Natural Science Foundation of China (21603023) the PetroChina Innovation Foundation, China (2014D-5006-0501)~~
【分类号】：O643.32

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