Preparation and formation mechanism of Al-YNU-1 using highly acid-treated Fe-YNU-1 molecular sieve as a silica source

Abstract

Al-YNU-1 molecular sieve was synthesized through the post-synthesis method from highly acid-treated Fe-YNU-1 in the presence of piperidine. The effects of silica sources, structure-directing agents, composition of raw materials, and crystallization conditions on the structure and Al content of Al-YNU-1 were investigated. Optimizing the Al and H 2 O amounts in the synthesis mixture, as well as the crystallization time and the acid treatment conditions applied to the as-synthesized lamellar precursors, produced a large increase in the content of Al in the Al-YNU-1 framework, to nearly double that of a sample prepared using deborated MWW as the silica source. To form Al-YNU-1, it is essential to remove most of the template molecules and framework Al species from the lamellar Al-MWW precursor by acid treatment, and to have a large number of defect sites within the Si source. 以Pd(OAc) 2 为主催化剂, 以Cu为助催化剂, 以碘为氧化剂, 高效地实现了吲哚与苯炔直接羰化合成吲哚-3-炔酮, 并优化了反应条件. 结果表明, 该催化剂体系对带有不同取代基的吲哚、端炔类化合物具有非常好的适用性, 最高分离产率可达94%. 生成的吲哚-3-炔酮产物可进一步与叠氮化钠和溴苄一锅反应, 高产率地得到3-甲酰三唑基吲哚类化合物. 由于原料来源简单, 产率高, 且两类产物都是重要的中间体, 因此该方法具有一定的应用价值. Al-YNU-1 zeolite was post-synthesized using DeFe-YNU-1 as a silica source. In this way, its framework Al content was significantly increased. The chemical composition of the synthesis gel and the acid-treatment conditions of the as-synthesized precursor have great effects on the formation of Al-YNU-1.