Au/TS-1 catalyst for propene epoxidation with H₂/O₂: A novel strategy to enhance stability by tuning charging sequence

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• 作者：Xiang Feng ; Yibin Liu ; Yichuan Li ; Chaohe Yang ; Zhihua Zhang ; Xuezhi Duan ; Xinggui Zhou and De Chen
• 刊名：AIChE Journal
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：62
• 期：11
• 页码：3963-3972
• 全文大小：764K
• ISSN：1547-5905

文摘

For propene epoxidation with H₂ and O₂, the catalytic performance of Au/TS-1 catalyst is extremely sensitive to preparation parameters of deposition-precipitation (DP) method. In this work, effect of charging sequence in DP process on catalyst structure and catalytic performance of Au/TS-1 catalyst is first investigated. For different charging sequences, the compositions of Au complexes (e.g., [AuCl(OH)₃]⁻) and pore property of TS-1 (i.e., with or without H₂O prefilling micropores) could affect the transfer of Au complexes into the micropores, resulting in different Au locations and thus significantly different catalytic performance. Notably, when TS-1 is first filled with H₂O and then mixed with Au complexes, the reduced Au/TS-1 catalyst could expose Au nanoparticles on the external surface of TS-1 and show high stability. The results provide direct evidence showing that micropore blocking is the deactivation mechanism. Based on the results, a simple strategy to design highly stable Au/Ti-based catalysts is developed.