APT reconstruction of a methanol-to-hydrocarbons (MTH) reacted SAPO-34 zeolite catalyst (left). A magnified view of the SAPO-34 framework containing a trapped hydrocarbon and a 5-atom Si cluster.
Scientific Achievement
APT reconstruction of a methanol-to-hydrocarbons (MTH) reacted SAPO-34 zeolite catalyst (left). A magnified view of the SAPO-34 framework containing a trapped hydrocarbon and a 5-atom Si cluster. (hi-res image)
Atom Probe Tomography (APT) determined that Si islands are tens of atoms in size for the commercially relevant methanol-to-hydrocarbons conversion catalyst SAPO-34.
Significance and Impact
Si islands, key to material performance, have only been detected previously in SAPO-34 using NMR spectroscopy, which can’t locate individual atom positions or determine island size.
Research Details
– The nanoscale chemical distribution of template containing, calcined, and MTH reacted SAPO-34 catalysts with different Si contents have been determined using APT.
– Analysis of simulated APT data show that small Si islands can be identified using the radial distribution function (RDF) algorithm with limited spatial blurring.
J. E. Schmidt, L. Peng, A. L. Paioni, H. L. Ehren, W. Guo, B. Mazumder, D. A. Matthijs de Winter, O. Attila, D. Fu, A. D. Chowdhury, K. Houben, M. Baldus, J. D. Poplawsky, and B. M. Weckhuysen, "Isolating clusters of light elements in molecular sieves with atom probe tomography," J. Am. Chem. Soc. 140, 9154 (2018). DOI: 10.1021/jacs.8b04494
