Open AccessThe role of XAFS in the in situ and ex situ elucidation of active sites in designed solid catalysts
Author(s) -
Thomas John Meurig,
Sankar Gopinathan
Publication year - 2001
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s090904950001935x
Subject(s) - x ray absorption fine structure , in situ , catalysis , chemistry , active site , chemical engineering , materials science , organic chemistry , physics , spectroscopy , engineering , quantum mechanics
New mesoporous and microporous catalysts based on silica, aluminophosphates, or aluminophosphates containing one or other of the heteroatoms Ti, Co, Mn, Fe and Cr, are ideally suited for study by X‐ray absorption fine structure (XAFS). The information derived from X‐ray absorption near‐edge structure (XANES) and extended X‐ray absorption fine structure (EXAFS) elucidates the nature of the catalytically active site, generally (but not invariably) under in situ conditions. This, in turn, provides new insights into the mechanism of the catalysis and suggests methods of improving the performance of the original catalyst. In this way, significant advances have recently been made in designing catalysts for the selective oxidation of alkanes, for the epoxidation of alkenes and for the dehydration of alcohols to yield olefins. Combined with density functional theory (DFT) computations, XAFS studies have also yielded fresh insights into the architecture of nanoparticle catalysts, such as Ru 12 Cu 4 C 2 supported on mesoporous silica.