TY - GEN A1 - Grönke, Martin A1 - Arrozi, Ubed S. F. A1 - Bronkalla, Nadine A1 - Schmidt, Peer A1 - Valldor, Martin A1 - Oswald, Steffen A1 - Woodcock, Thomas G. A1 - Eckert, Victoria A1 - Hao, Qi A1 - Plüschke, Laura A1 - Lederer, Albena A1 - Nielsch, Kornelius A1 - Büchner, Bernd A1 - Kaskel, Stefan A1 - Hampel, Silke T1 - Layered α-TiCl₃: Microsheets on YSZ Substrates for Ethylene Polymerization with Enhanced Activity T2 - Chemistry of Materials N2 - The transition metal halide α-titanium(III) chloride (α-TiCl₃) is a layered two-dimensional compound and a well-established Ziegler–Natta catalyst for the polymerization of ethylene. A new synthesis technique is used to obtain thin sheets of α-TiCl₃ that show exceptional physical properties in contrast to their bulk counterparts, due to an enlarged surface-to-volume ratio. Chemical vapor transport (CVT) of α-titanium(III) chloride directly on substrates results in microsheets that exhibit an improved catalytic effect. For rational planning of synthesis conditions, thermodynamic simulations of occurring gas-phase equilibria were performed. Based on these calculation results, crystal growth was achieved by adding GaCl₃via pure short term CVT in a temperature gradient of 700–600 K on yttrium-stabilized zirconia (YSZ) substrates. Phase pure, as-grown, single crystal sheets with high crystallinity and a thickness of around 4 μm were obtained. These thin sheets of α-TiCl₃ on YSZ substrates were implemented as catalysts for the ethylene polymerization reaction. A significant improvement of catalytic activity of 16% was achieved, probably due to an increased surface-to-volume ratio. As a highlight, the as-grown microsheets were exfoliated subsequently to a thickness lower than 200 nm and an even higher catalytic activity of up to 24% was confirmed experimentally due to delamination effects. This is the first time that an improved catalytic effect of α-TiCl₃ is observed as a result of downscaling from bulk to microsheets by CVT. KW - Crystal growth KW - Chemical vapor transport KW - Thermodynamic modeling KW - 2D layered compounds KW - Halides KW - Nanocrystals (1) Y1 - 2019 UR - https://opus4.kobv.de/opus4-UBICO/frontdoor/index/index/docId/24309 UR - https://pubs.acs.org/doi/10.1021/acs.chemmater.9b01818 VL - 31 IS - 14 SP - 5305 EP - 5313 ER -