2026-04-14T02:26:50Zhttps://recercat.cat/oai/request

oai:recercat.cat:10256/243502024-05-22T11:40:03Zcom_2072_452966com_2072_2054col_2072_452968

2024-05-22T11:40:03Z urn:hdl:10256/24350 Implementation of a fast method for the evaluation of the effect of external electric fields on catalysis Pey Costa, Guillem FDBβ Funcional de densitat, Teoria del Ciclització (Química) Density functionals Ring formation (Chemistry) Reaccions químiques regioselectives Regioselectivity reactions The concentration of CO2 has over the past century increased exponentially. The core of the issue lies in the high efficiency of CO2 to absorb and remit IR radiation back to Earth’s surface. Although CO2 is the main responsible, there are other gases sharing the same characteristic and they are known as Greenhouse Gases. As a consequence of having a higher concentration of them in the atmosphere, the IR radiation cannot escape and is kept inside leading to a higher mean global temperature. In the same way plants use photosynthesis to reduce CO2 to obtain glucose, modern chemistry has developed a process known as artificial photosynthesis, that uses a catalyst to transform CO2 into other high-interest products, such as methanol. This work studies a disproportionation mechanism of CO2 into carbon monoxide, our interest product, and carbonate catalysed by a cobalt complex. Due to CO’s high stability with the metallic centre, a potential well is generated which hinders a second catalytic turn. On the other hand, the appropriate application of electric fields into chemical systems can induce the catalysis of a reaction, or inhibit it, and even affect the selectivity. With the FDBβ method, the effect of electric fields can be computationally modelled by only computing the electric properties (dipole moment, polarisability, ...) of the involved chemical species. Mathematically, it is based on the Taylor series expansion of the field-dependent electronic energy, where the coefficients are the electric properties. Then, to define the reaction’s thermochemistry the expansions of products, or transition states, and reactants are subtracted following its stoichiometry. In this work, it has been demonstrated that the FDBβ is an excellent tool to study the effect of electric fields on reactivity. Furthermore, we have developed a FORTRAN95 code capable of finding the minimum electric field required to impose a preestablished barrier or energy reaction. By means of the FDBβ the effect on catalysis of an electric field has been studied on the catalytic reduction CO2-to-CO studied in this work. On one hand, it is found the effect of a positive electric field on the Z axis favours the CO release. In contrast, although the effect of a negative field on the Y axis hinders the previous process, it enhances the kinetics of the reaction stabilising the formation of the transition state that determines the TOF 9 2024-05-22T11:40:03Z 2024-05-22T11:40:03Z 2023-07 info:eu-repo/semantics/bachelorThesis http://hdl.handle.net/10256/24350 Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ info:eu-repo/semantics/openAccess Química (TFG)