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Understanding hydroxyl radicals addition to CO[formula omitted] on [formula omitted]-Fe2O3(1 1 0) surface photocatalyst for organic compounds production.

Understanding hydroxyl radicals addition to CO[formula omitted] on [formula omitted]-Fe2O3(1 1 0) surface photocatalyst for organic compounds production.

Authors :
Castro-Ocampo, O.
Celaya, Christian A.
González-Reyes, L.
Hernández-Pérez, I.
Garibay-Febles, V.
Jaramillo-Quintero, Oscar A.
Lara-García, Hugo A.
Muñiz, Jesús
Suárez-Parra, R.
Source :
Fuel. Feb2022:Part C, Vol. 310, pN.PAG-N.PAG. 1p.
Publication Year :
2022

Abstract

In this work, Density Functional Theory (DFT) calculations were performed to assess the photo-catalytic properties of hematite (α -Fe 2 O 3) and the atomistic modeling of the CO 2 conversion mechanism to organic molecules on such a surface. The reaction pathways for the CO 2 simulated photo-transformation were modeled with the string method. The reaction mechanism obtained by DFT calculations evidenced the H 2 O 2 molecules reduction instead of the CO 2 reduction at the first step, inducing • OH radical formation. The following CO 2 activation is induced by the addition of the • OH radical through one of the π ∗ bonds of CO 2 molecule, unlike the commonly reported CO 2 reduction, resulting in the bicarbonate anion. The emergence of carbonic acid is followed by carbon reduction reactions up to methanol. According to the adsorption energies and topological analysis of the bond critical points, the intermediates exhibited closed-shell interactions with the hematite surface. Electronic structure properties were evaluated at the DFT+ U + J level. Opto-electronic parameters were also evaluated experimentally; giving validity to the results obtained by the DFT. This work also shows the first theoretical insight into the conversion of CO 2 with H 2 O 2 into H 2 CO 3 , HCOOH, CH 2 O and CH 3 OH on the hematite (1 1 0) surface. Additionally, to support the theoretical elucidation, a mixture of iron oxides (Fe 2 O 3 - FeOOH) nanoparticles were prepared in accordance to recent published results suggesting a heterogeneous catalytic process, instead a homogeneous Fenton's method to evaluate the photocatalytic properties and the redox-potential to degrade CO 2. One of the predominant phases observed in the iron oxide mixture corresponds to hematite. Moreover, the photocatalytic process of CO 2 conversion with iron oxide nanoparticles was experimentally performed. The formation of methanol was evidenced via FTIR analysis. [Display omitted] • Hematite in the presence of H 2 O 2 is suitable for CO 2 conversion to organic compounds. • DFT+U+J approach accurately predicts electronic properties of hematite structure. • Simulation predicts photocatalytic potential of hematite surface for CO 2 conversion. • CO 2 activation in photocatalysis can be achieved by addition reaction in one step. • CO 2 photocatalysis on a α -Fe 2 O 3 surface is theoretically and experimentally verified. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00162361
Volume :
310
Database :
Academic Search Index
Journal :
Fuel
Publication Type :
Academic Journal
Accession number :
154049589
Full Text :
https://doi.org/10.1016/j.fuel.2021.122465