2026-04-13T01:36:51Zhttps://recercat.cat/oai/requestoai:recercat.cat:10256/243502024-05-22T11:40:03Zcom_2072_452966com_2072_2054col_2072_452968
RECERCAT
author
Pey Costa, Guillem
2024-05-22T11:40:03Z
2024-05-22T11:40:03Z
2023-07
http://hdl.handle.net/10256/24350
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 TOF9
Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ info:eu-repo/semantics/openAccess
FDBβ
Funcional de densitat, Teoria del
Ciclització (Química)
Density functionals
Ring formation (Chemistry)
Reaccions químiques regioselectives
Regioselectivity reactions
Implementation of a fast method for the evaluation of the effect of external electric fields on catalysis
info:eu-repo/semantics/bachelorThesis