Projectdetails

A central challenge for the society in the coming decades is to secure an adequate and more sustainable supply of energy and chemicals. Concerns about the green house effect and the depletion of fossil fuels reserves necessitate the replacement of crude oil by alternative feedstocks on the short term. Biomass is a desirable renewable feedstock as it can in principle close the carbon cycle associated with the utilization of the biomass-derived liquid fuels. From biomass a large variety of chemicals and fuels can be produced to serve virtually every purpose that the oil-derived compounds currently serve. To efficiently utilize biomass, novel and improved catalytic processes must be developed that selectively alter or remove excessive functionalities from this renewable feedstock. In the transition period to a sustainable energy production from biomass, wind and solar as primary energy sources, more efficient utilization of natural gas is desirable as it is the cleanest of the available fossil fuels. There is a number of experimental research projects carried out in our group aimed at the rational design of novel catalytic processes for the selective valorization of biomass and natural gas as well as for the more sustainable production of bulk chemicals. Undoubtedly, rational design of novel catalytic materials and processes necessitate a deep molecular-level understanding of the reaction mechanisms underlying activity and selectivity patterns of the respective catalytic transformations. This project aims at the quantum chemical study of the reaction mechanisms and the fundamental factors that determine selectivity and reactivity of various catalytic processes such as selective oxidation of alcohols, liquid phase biomass reforming reforming, sugar dehydration, the direct formation of hydrogen peroxide, Fischer-Tropsch reaction as well as chemical transformations of carbon dioxide. The theoretical outcomes will form a solid basis for the improved understanding of these catalytic systems and provide input into the tailored design of novel catalytic systems. In our experience, such studies are extremely useful in synergy with experimental research. All the projects described below involve complementary experimental investigations.

This proposal is the continuation of our studies carried out within the projects SH-170-10 and SH-170-11. This application includes 8 sub-projects focused on quantum chemical studies of the above-mentioned catalytic processes. The focus is on density functional calculations. The first subproject (A) explores the catalytic reactivity of Cu- and Fe-modified high-silica zeolites in selective oxidation of hydrocarbons and deNOx processes. During last two years we have successfully studied the mechanism of methane activation over Cu-containing zeolites and the mechanism of catalytic oxidation of benzene to phenol over Fe-ZSM-5 material. Within this proposal we will utilize the thus obtained knowledge to test computationally the potential role of larger copper-oxo complexes stabilized in ZSM-5 matrix for the selective oxidation of methane. Besides this, we continue investigating the mechanism of catalytic N2O decomposition over Fe-containing ZSM-5 catalysts. Subproject B is devoted to the investigation of structure sensitivity of alcohol oxidation over transition metal catalysts and subproject C is related to the problem of CO2-free H2 production by biomass reforming. Within these subprojects we will continue exploring the mechanistic details of methane activation and elementary steps relevant to alcohol conversion over various transition metal surfaces including those supported on reducible oxides. Subproject D focuses on investigating the mechanism of the direct H2O2 synthesis by transition metal catalysts. Subproject E continues the computational study of the structure sensitivity of the Fisher-Tropsch reaction. Within the subproject F we continue investigating the molecular details of the mechanism of catalytic sugar transformations by acid catalysts. At this stage special attention will be devoted to understanding the mechanism of selective glucose isomerization to fructose by Sn-modified BEA zeolites in water. Subproject G will involve supporting computations aimed at unraveling mechanistic details of CO2 hydrogenation to formic acid in the presence of homogeneous catalysts. Within subproject H we will continue our studies on the chemical reactivity of La-modified low-silica zeolites in alkane activation.

The systems considered in this project involve complex structures of catalytic ensembles and extensive networks of elementary reactions. Computational studies of such systems using the state-of-the-art quantum chemical methods are very intensive and rely entirely on the availability of modern supercomputer facilities.