正丁烷在Au,Zn组合改性纳米HZSM-5上的催化转化(英文)

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

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.

An Au‐Zn‐modified HZSM‐5 catalyst was prepared using deposition‐precipitation and wet impreg‐ nation 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.