Seed-Assisted Interzeolite Conversion Strategy for Fabricating Lewis Acid Sn-CHA Zeolites.
Seed-Assisted Interzeolite Conversion Strategy for Fabricating Lewis Acid Sn-CHA Zeolites.
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DOI：
10.1021/acs.inorgchem.3c01376
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发表时间：
2023-07
影响因子：
4.6
通讯作者：
Xin Yan;Jiaxing Zhang;Tianlong Wang;Huifang Wu;Lu Fang;Lin-an Liu;Limin Ren;Xinwen Guo
中科院分区：
文献类型：
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作者：
Xin Yan;Jiaxing Zhang;Tianlong Wang;Huifang Wu;Lu Fang;Lin-an Liu;Limin Ren;Xinwen Guo
小孔路易斯酸沸石在小分子转化的形状选择反应中显示出越来越大的潜力。在本研究中，通过无氟、种子辅助的沸石间转化（IZC）途径制备了具有可调框架锡含量的Sn- cha。市售的脱铝USY作为母体样品，而种子在加速转化过程、提高目标沸石收率和引导附着生长途径方面发挥了至关重要的作用。值得注意的是，在IZC过程中捕获了具有半构建孔隙结构的原始沸石相，这代表了形成完整CHA结构和确保明确Sn状态的关键中间阶段。通过一系列技术，在多尺度上探索了详细的合成机理。所得Sn-CHA和原Sn-CHA在1,3-二羟基丙酮转化为乳酸甲酯方面表现出优异的催化性能。原sn - cha具有较大的孔径和Lewis酸性，是一种高效的葡萄糖异构化催化剂。
Small-pore Lewis acid zeolites have been showing increasing potential in shape-selective reactions regarding small-molecule conversion. In this study, Sn-CHA with tunable framework Sn contents was facilely prepared via a fluoride-free, seed-assisted interzeolite conversion (IZC) pathway. Commercially available dealuminated USY functioned as the parent sample, and seeding played a vital role in accelerating the transformation process, promoting the target zeolite yield, and guiding the attached-growth pathway. Notably, a proto-zeolite phase with a semi-constructed pore structure was captured during the IZC process, which represents a crucial intermediate stage for developing the complete CHA structure and ensuring a well-defined Sn status. The detailed synthesis mechanism was explored in multiscale by a series of techniques. The obtained Sn-CHA and proto-Sn-CHA exhibited excellent catalytic performance in converting 1,3-dihydroxyacetone to methyl lactate. Proto-Sn-CHA was proven to be a highly effective glucose isomerization catalyst owing to its larger pore size and Lewis acidic nature.