title: Structures, energetics and reaction mechanisms of nitrous oxide on transition-metal-doped and -undoped single-wall carbon nanotubes.
abstract: The catalytic activity of carbon nanotubes (CNTs) for the removal of greenhouse gases, like nitrous oxide (N(2)O), can be fine-tuned by metal doping. We modify the inert surfaces of CNTs with Sc, Ti and V transition metals in order to investigate their capability of converting N(2)O to N(2). The stable composite catalysts of Sc-, Ti- and V-doped (5,5)single-walled carbon nanotubes (SWCNTs), along with the unmodified one were investigated by periodic DFT calculations. Without metal doping, the N(2) O decomposition on the bare tube proceeds over a high energy barrier (54.3 kcal mol(-1)) which in the presence of active metals is reduced to 3.6, 8.0 and 10.2 kcal mol(-1) for V-, Ti- and Sc-doped (5,5)SWCNTs, respectively. The superior reactivity is a result of the facilitated electron transfer between the tube and N(2)O caused by the overlap between the d orbitals of the metal and the p orbitals of N(2)O.
authors.affiliation: Department of Chemistry, Faculty of Science, National Center of Excellence for Petroleum, Petrochemicals and Advanced Materials, Kasetsart University, Bangkok, Thailand.
authors.forename: Panvika
authors.initials: P
authors.lastname: Pannopard
authors.forename: Pipat
authors.initials: P
authors.lastname: Khongpracha
authors.forename: Chompunuch
authors.initials: C
authors.lastname: Warakulwit
authors.forename: Supawadee
authors.initials: S
authors.lastname: Namuangruk
authors.forename: Michael
authors.initials: M
authors.lastname: Probst
authors.forename: Jumras
authors.initials: J
authors.lastname: Limtrakul