Hierarchical Beta zeolites are successfully synthesized with hydrothermal method in the presence of polydiallyldimethylammonium chloride (PDADMA). Followed a dealumination process, hierarchical Sn-Beta are post-synthesized by the solid-gas reaction of dealuminated Beta zeolite with SnCl₄ vapor. All samples are charcterized with XRD, N₂ sorption, SEM and TEM. SEM images show that both Beta zeolite and Sn-Beta zeolite exhibit rough spherical-like morphology of about 500-900 nm in diameters, N₂ sorptions show the pore size distributions in micropore and mesopore ranges, indicating the formation of mesoporous Beta zeolites. It is proofed that Sn species are doped into the framework in a tetrahedral environment during solid-gas reaction and the introduction of Sn species has negligible impact on the structure of Beta zeolites. Furthermore, the dehydration of glucose into HMF which needs both Brönsted and Lewis acid is selected to evaluate the catalytic performance of hierarchical Sn-Beta. It displays good catalytic activity, the conversion of glucose (99%) and selectivity to HMF (42%) are higher than those of the conventional Beta (96% and 32%, respectively). This is attributed to the intra-crystalline mesoporous structure and efficient diffusion of reactant/product molecules. Moreover, the catalyst exhibits steady catalytic performance after the fifth repeated run.

在聚二烯丙基二甲基氯化铵（PDADMA）存在下，采用水热法成功合成了分级β沸石。继脱铝过程之后，通过脱铝的Beta沸石与SnCl ₄蒸气的固相反应，可以对Sn-Beta进行后合成。所有样品均经XRD，N ₂吸附，SEM和TEM表征。SEM图像显示，β沸石和Sn-Beta沸石均呈现出直径约为500-900 nm的粗糙球形状形态，N ₂吸附显示出微孔和中孔范围内的孔径分布，表明形成了中孔β沸石。事实证明，在固相反应过程中，Sn物种在四面体环境中被掺杂到骨架中，Sn物种的引入对β沸石的结构影响可忽略不计。此外，选择了需要布朗斯台德酸和路易斯酸的葡萄糖脱水成HMF来评估分级Sn-β的催化性能。它显示出良好的催化活性，葡萄糖的转化率（99％）和对HMF的选择性（42％）高于常规Beta（分别为96％和32％）。这归因于晶体内的介孔结构和反应物/产物分子的有效扩散。此外，