Catalytic conversion of n-butane over Au-Zn-modified nano-sized HZSM-5

An Au-Zn-modified HZSM-5 catalyst was prepared using deposition-precipitation and wet impregnation methods. To obtain a better understanding of the relationship between catalyst characteristics and catalytic performance, a thorough study of various catalyst samples (HZSM-5, Au/HZSM-5, Zn/HZSM-5, and Au-Zn/HZSM-5) was performed. The interactions between Au and Zn species in Au-Zn/HZSM-5 were determined using ultraviolet-visible and X-ray photoelectron spectroscopies. Compared with Zn/HZSM-5, the introduction of Au to give Au-Zn/HZSM-5 effectively promotes the dehydrogenation and aromatization of n-butane, and also suppresses hydrogenolysis over Zn species. The n-butane conversion (70.8%) and selectivity for olefins and aromatics (61.98%) increased significantly. The dry gas selectivity also decreased significantly to 28.4%. Au-Zn-containing HZSM-5 is a useful catalyst for the conversion of light alkanes.

摘要采用沉积沉淀和浸渍法制备了Au-Zn组合改性HZSM-5催化剂. 并且对比研究了HZSM-5, Au/HZSM-5, Zn/HZSM-5和Au-Zn/HZSM-5催化剂的性质和催化性能. 采用UV-Vis和XPS表征揭示出Au-Zn/HZSM-5催化剂中Au物种与Zn物种的相互作用. 正丁烷探针反应结果表明, 在Zn/HZSM-5催化剂中引入Au有效地提高了正丁烷的脱氢芳构化性能, 同时抑制了正丁烷在Zn活性中心上的氢解副反应. 在相同条件下, 与Zn/HZSM-5催化剂相比, 正丁烷转化率由49.1%增加到70.8%, 烯烃和芳烃产物总选择性由57%增加到61.98%, 干气的选择性由31%降低至28.4%. 上述结果表明, Au-Zn/HZSM-5催化剂在轻烃芳构化反应中具有良好的催化性能.

Graphical AbstractAu-Zn/HZSM-5 was found to be an excellent catalyst for the light alkanes reaction. Its use significantly increased n-butane conversion, olefin and aromatic selectivity, and decreased dry gas selectivity.Figure optionsDownload as PowerPoint slide