Consequences of exchange-site heterogeneity and dynamics on the UV-visible spectrum of Cu-exchanged SSZ-13.

ABSTRACT: The speciation and structure of Cu ions and complexes in chabazite (SSZ-13) zeolites, which are relevant catalysts for nitrogen oxide reduction and partial methane oxidation, depend on material composition and reaction environment. Ultraviolet-visible (UV-Vis) spectra of Cu-SSZ-13 zeolites synthesized to contain specific Cu site motifs, together with ab initio molecular dynamics and time-dependent density functional theory calculations, were used to test the ability to relate specific spectroscopic signatures to specific site motifs. Geometrically distinct arrangements of two framework Al atoms in six-membered rings are found to exchange Cu²⁺ ions that become spectroscopically indistinguishable after accounting for the finite-temperature fluctuations of the Cu coordinatio

SUBMITTER: Li H 

PROVIDER: S-EPMC6385673 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature