Rational Design and HT Techniques Allow the Synthesis of New IWR Zeolite Polymorphs

Abstract

By combining a rational design of structure directing agents and high throughput and data mining techniques, it has been possible to obtain Ge-free ITQ-24 as pure silica as well as borosilicate polymorphs up to a Si/TIII ratio of 10. Al can be exchanged by B giving strong acid materials. Also, the availability of the pure silica material allows one to determine more precisely the crystal symmetry. This work opens the possibility to synthesize the Ge-free polymorphs of a large number of new germanosilicate structures reported in the last five years. This certainly will increase their possibilities for industrial application.

Combinatorial and High‐Throughput Materials Science

“…Pure silica ITQ24 as well as borosilicate polymorphs have thus become accessible. [354] The synthesis of zeolites with pore sizes larger than 14-membered rings was believed to be hindered by the required O-Si-O bond angles. HT techniques has led the research group of Corma to identifying the untypical synthesis conditions for the generation of a new silicogermanate (ITQ 33) large-pore zeolite with stable, linear 18-membered-ring channels.…”

Nano Catalysts for Diesel Engine Emission Remediation

“…[3][4][5] The partial replacement of tetravalent silicon in zeolites with trivalent aluminum results in acidic sites which are responsible for catalytic activity. 6 The efforts to tailor catalytic performance of zeolites include cation exchange, morphology modification of cage size and channel shape 7 to increase the density of active acidic sites, and replacement of aluminum with boron (borosilicate) 8 or gallium (galliosilicate) 9 to tune the acidity of the active sites. Cation exchange generally leads to mononuclear centers for catalytic activity although a dinuclear metallic core, Cu-(µ-O)-Cu, has been reported by Solomon et al as the effective catalytic site for O 2 activation.…”

Kombinatorische und Hochdurchsatz‐Techniken in der Materialforschung

“…Reine SiO 2 -ITQ24-und Borsilicat-Polymorphe wurden so zugänglich. [354] Lange war angenommen worden, dass die Synthese von großporigen Zeolithen mit größeren als 14-gliedrigen Ringen durch die hierfür erforderlichen O-Si-O-Bindungswinkel verhindert würde. Der Einsatz von HT-Techniken führte nun zu äußerst untypischen Synthesebedingungen für neuartige großporige Siliciumgermanatzeolithe (ITQ 33) mit stabilen linearen 18-Ring-Kanä-len.…”