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Mechanistic Insights into Catalytic Ethanol Steam Reforming Using Isotope‐Labeled Reactants
Author(s) -
Crowley Stephen,
Castaldi Marco J.
Publication year - 2016
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201604388
Subject(s) - chemistry , catalysis , ethylene , ethanol , isotopic labeling , steam reforming , dehydration , kinetic isotope effect , reaction mechanism , isotope , reaction intermediate , photochemistry , inorganic chemistry , organic chemistry , deuterium , biochemistry , hydrogen production , physics , quantum mechanics
Abstract The low‐temperature ethanol steam reforming (ESR) reaction mechanism over a supported Rh/Pt catalyst has been investigated using isotope‐labeled EtOH and H 2 O. Through strategic isotope labeling, all nonhydrogen atoms were distinct from one another, and allowed an unprecedented level of understanding of the dominant reaction pathways. All combinations of isotope‐ and non‐isotope‐labeled atoms were detected in the products, thus there are multiple pathways involved in H 2 , CO, CO 2 , CH 4 , C 2 H 4 , and C 2 H 6 product formation. Both the recombination of C species on the surface of the catalyst and preservation of the C−C bond within ethanol are responsible for C 2 product formation. Ethylene is not detected until conversion drops below 100 % at t =1.25 h. Also, quantitatively, 57 % of the observed ethylene is formed directly through ethanol dehydration. Finally there is clear evidence to show that oxygen in the SiO 2 ‐ZrO 2 support constitutes 10 % of the CO formed during the reaction.