AXAFS技术在Ni/ZnO吸附剂上模型油反应吸附脱硫机理研究中的应用

原子X射线吸收精细结构（AXAFS）由吸收原子的外围束缚电子对出射光电子波的背散射引起，AXAFS信号与嵌入原子势能、原子间隙势能和吸收原子电子密度的分布密切相关，可以作为精确的探针来探测原子的电子化学结构。研究利用AXAFS技术，以Ni/ZnO脱硫吸附剂为研究对象，探讨了模型油在不同气体气氛下的脱硫反应机理。结果表明，在氢气气氛下、350 ℃和3.0 MPa的条件下，从Zn元素的原位AXAFS谱图中可观察到脱硫过程中Zn元素的化学态变化。根据这些结果，揭示了氢气在脱硫过程中的重要作用，阐述了原位反应条件下吸附剂中Zn元素的化学态变化。

An AXAFS study on the mechanism of reactive adsorption desulfurization of model oil over Ni/ZnO adsorbent

Atomic XAFS (AXAFS) originates from photoelectron scattering off electrons in bonds on the periphery of the absorber atom, the embedded-atom potential, the interstitial potential and the distribution of the absorber-atom electron density are all found to be important in determining the AXAFS intensity, hence AXAFS can be a very useful probe to monitor changes in the electronic and chemical structure of the absorber atom. In this work, we use AXAFS of Zn element to study the reaction mechanism of the calcined and the reduced adsorbent under different atmospheres, it is showed that hydrogen plays an important role in the desulfurization. In situ AXAFS of Zn element also exhibits the chemical structure evolution of Zn element during desulfurization at 350 ℃ and 3.0 MPa in the atmosphere of H₂.