EAGER: Catalytic Materials Lacking C-H Bonds for Petroleum Sweetening and Hydrocarbon Oxidations
The processing of hydrocarbon natural resources using air as the oxidant remains a major goal of catalytic science. While catalytic materials based on inorganic components are known, advances based on organic materials are limited by the fact that the currently known organic catalysts are labile and thus unstable with respect to the chemistry they promote. A key advance may be the generation of materials that can benefit from the large body of knowledge accumulated within organic chemistry. Professor Sergiu Gorun of Seton Hall University has in mind robust catalyts bioinspired by the enzyme Cytochrome P450, that is capable of oxidizing hydrocarbons. These organic catalysts are made robust due to C-H bond replacement by C-F bonds. Unlike the enzyme, the catalysts will utilize only air for oxidations.The field of catalysis will benefit since the work will provide insights into ways to reduce the deleterious effects, such as corrosion, of thiols in petroleum distillate fuels, as well as advancing the direct oxidation of methane, an abundant resource to provide other chemicals.
The project is aimed at synthesizing a family of perfluorinated metallo-phthalocyanines, designed to retain strong coordinating properties in spite of having strongly electron withdrawing perfluoroalkylated substituents. The metal complexes will be anchored on solid-state supports, including silica gel, via (i) the interaction of their bulky fluoro substituents with surface oxygen species andor (ii) the additional interactions between peripheral amino groups, planned to be introduced at the macrocycle ring, with the support surface. The presence of the fluoroalkyl ligand groups is expected to exacerbate the Lewis acidity of the coordinated metal and thus to favor the coordination of substrates. Redox active metals, such as cobalt, will be studied, while a non-redox one, for example zinc, will provide a control molecule, thus permiting the differentiation between metal vs. ligand-centered redox reactions for sulfur compound oxidation. The same catalysts, but including additional metals such as ruthenium, will be used for the oxidation of aliphatic hydrocarbons. In this case, the complexes will be encapsulated in inorganic frameworks, such as zeolites or mesoporous materials.
