Investigations Of Pincer Iridium Complexes For Glycerol Deoxygenation And For Alkane Dehydrogenation

Green chemistry is being paid increased attention with the growing awareness of the environmental impact of the chemical industry. Catalysis is important in the development of green processes as it reduces the waste that is generated and lowers the energy required. Abundant feedstocks such as natural gas or biomass can be catalytically converted to value-added chemicals. Catalysts are employed in a wide range of applications, and innovations in green catalysis are crucial to achieve sustainability. To reduce the dependency on the unsustainable petroleum feedstock, biodiesel has been recognized as an effective, sustainable alternative. During biodiesel production, by-product glycerol is generated in a large amount. Catalyst development for the deoxygenation of low-cost glycerol to value-added 1,3-propanediol is discussed in Chapter 2.Alkane dehydrogenation to olefin is energy-intensive due to the endothermic nature of the reaction. A selective, energy-efficient catalyst is essential for sustainability. Immobilization of a homogeneous catalysts on heterogeneous supports can provide active, selective catalysts with robustness and recyclability. The immobilization enables the implementation of gas-phase continuous-flow reaction design. In the flow system, the by-product H2 can be effectively removed to achieve higher TON. Chapter 3 demonstrates catalytic dehydrogenation and hydrogenation reactions by an immobilized (POCOP)Ir complex on silica. Since homogeneous (Phebox)Ir and (CCC)Ir complexes have been demonstrated to activate C-H bonds, immobilization of those complexes on silica were attempted. The synthesis of Phebox and CCC ligands with functional groups to allow immobilization to silica are outlined in Chapter 4.