Advanced Electrocatalytic Systems based on Transition Metal Dichalcogenides for Carbon Dioxide Utilization
thesisposted on 31.10.2017 by Pedram Abbasi
In order to distinguish essays and pre-prints from academic theses, we have a separate category. These are often much longer text based documents than a paper.
Conversion of carbon dioxide (CO2) to energy rich fuels powered by renewable energy resources is of significant importance to close the anthropogenic carbon cycle. However, the current electrochemical CO2 conversion systems are still far from being practically considerable mainly due to the high cost of electricity supply and low yield of CO2 conversion reaction. Among various electrocatalysts proposed for conversion of CO2 to value added products, the potential of transition metal dichalcogenides (TMDCs) as an advanced electrocatalysts for CO2 reduction in an ionic liquid based electrolyte has been demonstrated by our group. However, the electrocatalytic systems based on TMDCs are still in their early stages. This thesis is an effort to enahnce the feasibility of the electrocatalytic systems based on TMDCs. In chapter one, a general overview on the current estates of CO2 emmisions, its mitigation methods and the role of MoS2 as promising catalyst for CO2 utilization is presented. In chpater two, we investigate whether modifying the electronic structure of MoS2, and in particular active edge atoms, could tailor the binding strength and desorption rate of key intermediates during the CO2 reduction reaction. An optimal condition can potentially lead to a Sabatier effect resulting in an increased rate of product formation. In chpter three, an artificial leaf photosynthesis system has been developed to directly convert CO2 into the synthesis gas (CO and H2) in an acidic electrolyte using the energy from a sun simulator. By this concept CO2 can be converted to fuel without using external electricity source. This finding could potentially resolve the limiting factor for converting of CO2 to energy-rich chemicals using renewable energy