Morehead State University
Predicting the Reactions of CS2, OCS, and CO2 with Group IV and Group VI Transition Metal Oxides
Grade Level at Time of Presentation
Junior
Major
Chemistry
Minor
Psychology
Institution 23-24
Morehead State University
KY House District #
5
KY Senate District #
27
Faculty Advisor/ Mentor
Dr. Zachary Lee; Dr. David Dixon
Department
Biology and Chemistry
Abstract
Building on a recent serious of high level electronic structure studies of Lewis acid gas reactions with metal oxide sorbents, DFT (B3LYP and ωB97X-D) and CCSD(T) methods are being used to predict the Lewis acid-base addition (physisorption) and formation of metal oxide carbonate/thiocarbonate formation (chemisorption) reactions of CS2, OCS, and CO2 of CS2, OCS, and CO2 with Group IV (MO2)n and Group VI (MO3)n (n = 1 - 3) nanoclusters. For the Group IV oxides, chemisorption to form terminal carbonates and thiocarbonates is predicted to be the most favored, with thiocarbonate ligand binding energies slightly more exothermic than their carbonate analogues, consistent with the small differences in the CS2 C=S (105 kcal/mol) and CO2 C=O (127 kcal/mol) bond energies. For Group VI, only weak physisorption (< 10 kcal/mol exothermic) is predicted to occur for CO2, CS2, and OCS. These results are consistent with our previous studies of CO2, NO2, SO2, and H2O adsorption to Group IV and Group VI metal oxide clusters. The results of this work could have implications for the sequestration of CS2 from high-sulfur areas of arctic permafrost and also provides mechanistic insights into the possible reactions and products of OCS- and CS2-induced TiO2 degradation during the Claus Process.
Predicting the Reactions of CS2, OCS, and CO2 with Group IV and Group VI Transition Metal Oxides
Building on a recent serious of high level electronic structure studies of Lewis acid gas reactions with metal oxide sorbents, DFT (B3LYP and ωB97X-D) and CCSD(T) methods are being used to predict the Lewis acid-base addition (physisorption) and formation of metal oxide carbonate/thiocarbonate formation (chemisorption) reactions of CS2, OCS, and CO2 of CS2, OCS, and CO2 with Group IV (MO2)n and Group VI (MO3)n (n = 1 - 3) nanoclusters. For the Group IV oxides, chemisorption to form terminal carbonates and thiocarbonates is predicted to be the most favored, with thiocarbonate ligand binding energies slightly more exothermic than their carbonate analogues, consistent with the small differences in the CS2 C=S (105 kcal/mol) and CO2 C=O (127 kcal/mol) bond energies. For Group VI, only weak physisorption (< 10 kcal/mol exothermic) is predicted to occur for CO2, CS2, and OCS. These results are consistent with our previous studies of CO2, NO2, SO2, and H2O adsorption to Group IV and Group VI metal oxide clusters. The results of this work could have implications for the sequestration of CS2 from high-sulfur areas of arctic permafrost and also provides mechanistic insights into the possible reactions and products of OCS- and CS2-induced TiO2 degradation during the Claus Process.