Stockholm university

Stable 3D Extra-large Pore Zeolites. Direct synthesis, 1D-3D topotactic condensation and Interchain

Seminar

Date: Thursday 26 October 2023

Time: 10.00 – 11.00

Location: C516

You are welcome to the seminar by Prof. Miguel A. Camblor, Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas (ICMM-CSIC).

Prof. Camblor is Jungyoun Cho's opponent, he will defend his thesis on the same day.

Abstract of Prof. Camblor's talk: 
The pore size and pore dimensionality of zeolites are important for applications. Large crossing pores along the three directions maximize diffusion of guests, adsorbants, reactants and products and minimize overreaction and pore clogging. This explains the large success of FAU type zeolites, containing a 3D system of large pores opened through windows of 12 Si(Al)O4 tetrahedra, 12R. However, no stable zeolite with a 3D system of crossing extralarge pores (>12R, ELP) were known until recently, since the only such systems were not really zeolites but interrupted frameworks with germanosilicate or gallophosphate composition and, hence an intrinsically low stability. I would like to present our recent discovery of three silica-based zeolites with 3D ELP, a high thermal and hydrothermal stability and an improved catalytic and/or adsorption performance. The aluminosilicate ZEO-1 (16+12 × 16+12 × 16+12) was prepared by direct hydrothermal synthesis.[1] The pure SiO2 ZEO-3 (16 × 14 × 14) was prepared by an unprecedented 1D-to-3D topotactic condensation from a chain silicate.[2] Finally, (Ti)SiO2 ZEO-5 (20 × 16 × 16) was prepared by an equally unprecedented Interchain Expanded Reaction from the same chain silicate.[3] The structure of the three zeolite structures (and some intermediates) were determined by cRED, and all show full tetrahedral connectivity, a decreasing density that approaches that of water in the case of ZEO-5 (1.1 gcm-1) and a very large surface area (1000 to over 1500 m2g-1).