Premium
Formaldehyde Encapsulated in Lithium‐Decorated Metal‐Organic Frameworks: A Density Functional Theory Study
Author(s) -
Maihom Thana,
Choomwattana Saowapak,
Khongpracha Pipat,
Probst Michael,
Limtrakul Jumras
Publication year - 2012
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.201100642
Subject(s) - density functional theory , lithium (medication) , lithium metal , metal organic framework , metal , formaldehyde , chemistry , materials science , nanotechnology , inorganic chemistry , computational chemistry , organic chemistry , adsorption , electrode , medicine , endocrinology , electrolyte
The stability of monomeric formaldehyde encapsulated in the lithium‐decorated metal‐organic framework Li‐MOF‐5 was investigated by means of density functional calculations with the M06‐L functional and the 6‐31G(d,p) basis set. To assess the efficiency of Li‐MOF‐5 for formaldehyde preservation, we consider the reaction kinetics and the thermodynamic equilibrium between formaldehyde and its trimerized product, 1,3,5‐trioxane. We propose that trimerization of encapsulated formaldehyde takes place in a single reaction step with an activation energy of 34.5 kcal mol −1 . This is 17.2 kcal mol −1 higher than the corresponding activation energy in the bare system. In addition, the reaction energy of the system studied herein is endothermic by 6.1 kcal mol −1 and the Gibbs free energy (Δ G ) of the reaction becomes positive (11.0 kcal mol −1 ). Consequently, the predicted reverse rate for the trimerization reaction in the Li‐MOF‐5 is significantly faster than the forward rate. The calculations show that the oligomerization of formaldehyde in Li‐MOF‐5 is a reversible reaction, suggesting that such a zeolite might be a good candidate material for preserving formaldehyde in its monomeric form.