Effect of rhodium modification on structures of sulfiede Rh-Mo-K/Al2O3 catalysts studied by XAFS

• 来源期刊: 同步辐射装置用户科技论文集
• 学科: 化学
• 关键词: 铑 硫化Rh-Mo-K/Al2O3 催化剂
• 年，卷（期）: 1999,（1）
• 页码范围: 69-71
• 页数: 3页
• 分类号: O614.822

摘要

Local structures of the molybdenum sulfide species in the sultided Rh-Mo-K/Al2O3 catalysts with various rhodium loadings have been investigated by XAFS.From the fitting results.the Mo-Mo coordination number for the sample free of rhodium(ca.3.7) is similar to that for the crystalline MoS2,indicating that the supported sulfided molybdenum species mainly present as large pateches of MoS2-like slabs.For the rhodium-modified samples,however,the amplitudes of the Mo-S and Mo-Mo coordination shells are sharply reduced,revealing a high dispersion of the MoS2-like species in the catalysts,The scheme of the microstructures of the sulfided molybdenum species stabilized on the alumina support is discussed based upon the analysis of the EXAFS data.