Premium
Ethylene Epoxidation with Nitrous Oxide over Fe–BTC Metal–Organic Frameworks: A DFT Study
Author(s) -
Maihom Thana,
Choomwattana Saowapak,
Wannakao Sippakorn,
Probst Michael,
Limtrakul Jumras
Publication year - 2016
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201600836
Subject(s) - ethylene , ethylene oxide , acetaldehyde , chemistry , catalysis , oxide , decomposition , hydride , inorganic chemistry , metal , metal organic framework , activation energy , photochemistry , ethanol , organic chemistry , copolymer , adsorption , polymer
The epoxidation of ethylene with N 2 O over the metal‐organic framework Fe–BTC (BTC=1,3,5‐benzentricarboxylate) is investigated by means of density functional calculations. Two reaction paths for the production of ethylene oxide or acetaldehyde are systematically considered in order to assess the efficiency of Fe–BTC for the selective formation of ethylene oxide. The reaction starts with the decomposition of N 2 O to form an active surface oxygen atom on the Fe site of Fe–BTC, which subsequently reacts with an ethylene molecule to form an ethyleneoxy intermediate. This intermediate can then be selectively transformed either by 1,2‐hydride shift into the undesired product acetaldehyde or into the desired product ethylene oxide by way of ring closure of the intermediate. The production of ethylene oxide requires an activation energy of 5.1 kcal mol −1 , which is only about one‐third of the activation energy of acetaldehyde formation (14.3 kcal mol −1 ). The predicted reaction rate constants for the formation of ethylene oxide in the relevant temperature range are approximately 2–4 orders of magnitude higher than those for acetaldehyde. Altogether, the results suggest that Fe–BTC is a good candidate catalyst for the epoxidation of ethylene by molecular N 2 O.