Dış Kaynaklı Proje Süreçleri Yönetim Sistemi
Karatok M. (Yürütücü), Özgüven F., Koraş R., Bayram C.
Chemical production accounts for nearly 25% of energy use worldwide and forecasts to global energy demand project this number to rise to 45% by 2040. Fossil-based fuels are the major energy sources in the chemical industry therefore a large amount of greenhouse gasses is released to the environment in chemical production processes. Current trends in energy supply and use in the chemical industry are economically and environmentally unsustainable. To make chemical production processes sustainable, my future research will focus on boosting energy efficiency in the chemical industry.
Chemical transformations from raw materials to desired products occur on a catalyst, which is a substance that increases the rate of a chemical reaction. Catalysts simply consist of active surfaces (usually transition metals and metal oxide nanoparticles) where chemical reactions occur, and a support material to provide mechanical stability. The catalytic materials that are currently in use in the chemical industry suffer on several counts. One of the major problems is that they are not very selective to desired products therefore unwanted side products are produced, which also bring additional separation costs. Another important problem is that catalysts lose their activity (called ‘deactivation’) during operation because some reaction intermediates such as carbon monoxide, and/or high carbon content substances (i.e., coke) strongly bind to the active sites and poison the catalysts. In order to reduce the energy consumption and negative environmental impacts of the chemical industry, my research will tackle these major problems and seek highly reactive, selective, and robust catalytic materials for key chemical reactions.
To address the current issues in catalytic materials, the main objective of my research will be to identify the catalytic properties of a new type of catalyst that contains dilute bimetallic alloy nanoparticles as active substances. Catalytic properties of bimetallic alloys have been extensively studied in the last few decades. These alloys mostly show unique catalytic properties compared to their counterparts because intermixing two dissimilar atoms alters the electronic structure of the individual atoms and changes the binding characteristics of reactants on catalytic surfaces. In recent years, theoretical predictions and atomic-scale model studies indicated that specific structural configurations in alloys (e.g., isolated single atoms of active metals, ensembles in certain sizes, etc.) exhibit exceptional selectivity and/or stability. These specific structures can only be formed when the corresponding metal concentration is low (i.e., dilute). Thus, dilute alloys are considered as a new class of catalysts that have the potential to remove the current limitations of the chemical industry.
Despite their high potential, a detailed structural understanding of dilute bimetallic alloys is lacking due to the dilute nature of the alloys. To design the most efficient catalytic materials, fundamental working principles must be uncovered which is possible by investigating structure-reactivity relationships on catalytic materials. However, the exact surface composition and structure of the dilute alloys cannot be fully resolved even with the most advanced spectroscopic and microscopic techniques. My research offers an alternative way to quantify the active sites (i.e., dilute metal atoms) at nanoparticle surfaces using temporal analysis of products (TAP) reactor system so that the surface structure of dilute alloy nanoparticles and their functionality can be fully understood. Therefore, my research plan has the potential to make a large impact in the field of catalysis.