Computational studies of manganese based homogeneous catalysts for CO2 hydrogenation reactions

Abstract

The catalytic conversion of carbon dioxide into carbon-based chemicals/fuels such as carbon monoxide, formic acid, methanol, and higher alcohols via hydrogenation has been attracting significant attention due to the evident reasons of being an efficient approach of hydrogen storage as well as environmental friendliness. In past decades, homogeneous catalysts with the noble metal centers have drawn substantial interest as they show high product selectivity and are easy to tune by ligand modifications. However, there is a persistent necessity to reduce the cost of the catalysts by using non-noble metal-based catalysts, such as iron, cobalt, nickel, and manganese, which can be efficient for CO2 hydrogenation reaction. Also, the modification of ligands to increase their involvement in the reaction provides a great tool for the designing of more efficient catalysts. Ligands which can undergo change of oxidation states during the catalytic reaction via electrochemical or cleavage/formation of the chemical bond are called a redox (for electrochemical) or bifunctional ligand (for bond cleavage/formation). In recent time, several experimental studies have observed the enhanced catalytic activity using redox and bifunctional ligand-based catalysts for CO2 hydrogenation reaction. However, the exactly involved mechanisticpathways are still needed to be investigated in this field to advance the possibility of non-noble metal-based catalysts for the various types of CO2 hydrogenation reactions. Therefore, the cooperative ventures of both experimental and theoretical investigations are very much needed for the productive development of cooperative ligand based non-noble catalyst for the efficient CO2 hydrogenation as well as other chemical reactions. The contents of each chapter included in the thesis are discussed briefly as follows: