Synthesis of aluminophosphate molecular sieves with AFI topology substituted by alkaline earth metal and their application to solid acid catalysis

Investigating site-specific interactions and probing their role in modifying the acid-strength in framework architectures

“…[32] In stark contrast, the isopropylation of benzene requires the involvement of strong Brønsted acid sites, in order to activate isopropanol. [33] By unifying the results of the 45 complementary catalytic tests, and by employing in situ FTIR spectroscopy in combination with suitable probe molecules that would reveal the nature and strength of the acid sites, the influence of zinc (incorporation) could be suitably rationalised. It was hoped that the above studies would facilitate structure-50 property correlations to be established, which could lead to the design and fabrication of specific active sites for targeted acidcatalysed transformations.…”

Zincoaluminophosphate Molecular Sieves with AFI and ATS Topologies: Synthesis by Dry-Gel Conversion Methods and Their Catalytic Properties in the Isopropylation of Biphenyl

“…stage heating protocol, which was effective for the synthesis of MgAPO-36, 20,21) was introduced to for the optimization of the formation of ZnAPO-36 by VPT method. ZnAPO-36 was also contaminated with ZnAPO-5 in SAC method even at the same initial gel composition and heating protocol: this may be due to the decrease of SDA during drying the gel, because some of SDA may be evaporated with water, which is not sufficient for pure phase formation of ZnAPO-36.…”

“…The similar observation was seen in the synthesis of MgAPO-36 synthesis. 20,21) ZnO/Al 2 O 3 ratio in the initial gel composition influenced the crystallization of ZnAPO-36 ( Table 2, entries [16][17][18][19][20][21]. The ratio between 0.1-0.25 gave pure phase ( Table 2, entries 16-18, 20, and 21); however, the increase of the ratio to 0.43 resulted in contamination with impurities ( Table 2, entry 19).…”

“…[12][13][14][15][16][17] In comparison with the conventional hydrothermal synthesis method, these new methods have the advantages for environmental conscious synthesis of molecular sieves: the expansion of chemical compositions, the reduction of the SDA concentration, high conversion of gel, formation of uniform fine particles with high crystallization, minimization of waste disposal etc. [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] Dry-gel conversion (DGC) method is a synthetic technique using dry gel without bulk aqueous phase, [12][13][14] and is classified to two different but interrelated methods: vapor-phase transport (VPT, as used by Kim et al) 12) and steam-assisted conversion (SAC, as used by Matsukata et al) 13,14) methods. We recently described the convenient synthesis of maganesioaluminophosphates with AFI and ATS topologies.…”

“…We recently described the convenient synthesis of maganesioaluminophosphates with AFI and ATS topologies. [18][19][20][21] Brønsted acidity of zincoaluminophosphate, such as ZnAPO-5 and ZnAPO-36, leads to interesting candidates for shape-selective solid acid catalysis for the alkylation of polynuclear aromatics to symmetrical substituted products, such as 4,4 0 -dialkylbiphenyl from biphenyl (BP). 28,29) ZnA-PO-5 (topology: AFI) has one-dimensional 12-ring straight channel along [001] with symmetrical pore entrance of 0:73 Â 0:73 nm.…”