Theoretical Investigation of W(CO)6 and CO Selenization Process

Authors : Nadire NAYİR

Pages : 283-291

Doi:10.16984/saufenbilder.1038357

View : 17 | Download : 8

Publication Date : 2022-04-30

Article Type : Research Paper

Abstract :Detailed atomic-level insight into the mechanism of Winsert ignore into journalissuearticles values(CO);6 and CO selenization is essential for the fabrication of cheap and environmentally benign transition metal chalcogenides such as MoS2 and WSe2. Earlier discussions in literature have focused mainly on the CO methanation by sulfur and its derivatives but H2Se mediated CO methanation at the atomic level is yet to be explored. First-principles calculations and ReaxFF-based molecular dynamics simulations are conducted here to explore the relative stabilities of intermediates formed during the gas-phase interactions of Winsert ignore into journalissuearticles values(CO);6 and H2Se, determined associated reaction energies and kinetic barriers. The methanation of CO, which is released from the organometal, by H2Se is further investigated. The results indicate that the chain reactions of Winsert ignore into journalissuearticles values(CO);6 and H2Se lead to the formation of a thermodynamically stable end product of Winsert ignore into journalissuearticles values(SeH);2Se2. Depending on the temperature, Winsert ignore into journalissuearticles values(HSe);2Se2 is expected to go through a last uphill reaction by releasing H2Se into the environment and evolving into a WSe3 molecule. Additionally, the dehydrogenation of organometallic molecules is thermodynamically feasible but kinetically controlled, requiring a significant activation energy. When all CO groups are released from the W atom, the H2 release from W-compund becomes nearly barrierless. Since CO radical groups are dominant byproducts formed during the MOCVD chain reactions but in a chalcogen rich environment, this work also shed light into the CO selenization during the growth of transition metal diselenides insert ignore into journalissuearticles values(e.g., WSe2, MoSe2, CrSe2); and discusses the formation of potential products such as CSe2, CH4, H2Se, CO, H2O, Se2.
Keywords : Density functional theory, ReaxFF molecular dynamics, W CO, 6 and H2Se interactions, CO methanation