Unexpected crystal growth modifier effect of glucosamine as additive in the synthesis of SAPO-35

Effect of framework topology of SAPO catalysts on selectivity and deactivation profile in the methanol-to-olefins reaction

“…Prior to catalyst testing and characterization, the organic template and the water trapped within the micropores of the as-synthesized solids were removed by calcination at 823 K. Silicoaluminophosphate SAPO-35 was prepared from a synthesis gel in which the reactants were combined in the proportions detailed in Table 2. According to the procedure followed [46][47][48], aluminum hydroxide hydrate (Sigma-Aldrich) was dispersed in deionized water (33% of the total weight of water required) in a beaker, and a 34 wt% aqueous solution of orthophosphoric acid (Sigma-Aldrich, 85%) was added slowly to the suspension. The mixture was stirred for two hours before adding the fumed silica (Aerosil 200, Degussa) and the remaining amount of water.…”

Complex relationship between SAPO framework topology, content and distribution of Si and catalytic behaviour in the MTO reaction

“…In our experience, most of the SAPO samples incorporate Si easily up to a certain concentration, and normally the molar Si/Al ratios in the solids are close to that from gels. 32,41 However, the topological differences and the structure directing agent used in the synthesis also play an important role, controlling both the silicon incorporation and the silicon distribution in the framework. 46 As shown in Table 1, the silicon content of all SAPO samples increases with the amount of silicon precursor in the synthesis gels, although each framework topology shows different silicon incorporation yield.…”

“…• SAPO-35 was prepared following the same procedure reported elsewhere, 40,41 from gels with molar composition 1 Al2O3 : 1 P2O5 : x SiO2 : 1.5 HMI : 55 H2O, crystallized at 473 K for 24 h. According to such procedure, aluminium hydroxide hydrate (Sigma-Aldrich) was dispersed in deionized water using one third of the total weight of water, and an aqueous solution (34 wt%) of orthophosphoric acid (Sigma-Aldrich, 85%) was slowly added to the suspension. The mixture was vigorously stirred for 2 h before adding fumed silica (Aerosil 200, Degussa) along with the remaining amount of water.…”

Organic Mesopore Generating Agents (OMeGAs) for Hierarchical Zeolites: Combining Functions on Multiple Scales

“…Various zeolite growth modifiers, including alcohols, amines, organophosphine oxides, crown compounds, cationic polymers, and peptoids have achieved a high degree of control over zeolite crystal morphology for silicalite‐1, ZSM‐5, zeolite L, SSZ‐13, and ZSM‐22 beyond what is attainable in the absence of ZGMs. Some zeotype molecular sieves have been tuned with ZGM, such as the modification of silicoaluminophosphate SAPO‐35 mophology through the addition of glucosamine . The organic small molecule ZGMs usually have functional groups that bind to particular crystal faces, such as a polar amine group or hydroxyl group …”

“…Some zeotype molecular sieves have been tuned with ZGM, such as the modification of silicoaluminophosphate SAPO-35 mophology through the addition of glucosamine. [28] The organic small molecule ZGMs usually have functional groups that bind to particular crystal faces, such as a polar amine group or hydroxyl group. [25c] The interactions between the ZGMs and the growing zeolite framework can include van der Waals forces, electrostatic interactions, hydrogen bonding, and π-π stacking.…”