Computational Study on the Water Corrosion Process at Schreibersite (Fe2NiP) Surfaces : from Phosphide to Phosphates
Pantaleone, Stefano (Università degli Studi di Torino. Dipartimento di Chimica)
Corno, Marta (Università degli Studi di Torino. Dipartimento di Chimica)
Rimola Gibert, Albert (Universitat Autònoma de Barcelona. Departament de Química)
Balucani, Nadia (Università degli Studi di Perugia. Dipartimento di Chimica, Biologia e Biotecnologie)
Ugliengo, Piero (Università degli Studi di Torino. Dipartimento di Chimica)

Data:	2023
Resum:	Phosphorus (P) is a fundamental element for whatever form of life, in the same way as the other biogenic macroelements (SONCH). The prebiotic origin of P is still a matter of debate, as the phosphates present on earth are trapped in almost insoluble solid matrixes (apatites) and, therefore, hardly available for inclusion in living systems in the prebiotic era. The most accepted theories regard a possible exogenous origin during the Archean Era, through the meteoritic bombardment, when tons of reactive P in the form of phosphide ((Fe,Ni)3P, schreibersite mineral) reached the primordial earth, reacting with water and providing oxygenated phosphorus compounds (including phosphates). In the last 20 years, laboratory experiments demonstrated that the corrosion process of schreibersite by water indeed leads to reactive phosphates that, in turn, react with other biological building blocks (nucleosides and simple sugars) to form more complex molecules (nucleotides and complex sugars). In the present paper, we study the water corrosion of different crystalline surfaces of schreibersite by means of periodic DFT (density functional theory) simulations. Our results show that water adsorbs molecularly on the most stable (110) surface but dissociates on the less stable (001) one, giving rise to further reactivity. Indeed, subsequent water adsorptions, up to the water monolayer coverage, show that, on the (001) surface, iron and nickel atoms are the first species undergoing the corrosion process and, in a second stage, the phosphorus atoms also get involved. When adsorbing up to three and four water molecules per unit cell, the most stable structures found are the phosphite and phosphate forms of phosphorus, respectively. Simulation of the vibrational spectra of the considered reaction products revealed that the experimental band at 2423 cm-1 attributed to the P-H stretching frequency is indeed predicted for a phosphite moiety attached to the schreibersite (001) surface upon chemisorption of up to three water molecules.
Ajuts:	European Commission 865657 Agencia Estatal de Investigación PID2021-126427NB-I00 European Commission 811312
Drets:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Llengua:	Anglès
Document:	Article ; recerca ; Versió publicada
Matèria:	Meteorites ; Phosphorus problem ; DFT ; Prebiotic chemistry ; Water corrosion
Publicat a:	ACS earth and space chemistry, Vol. 7, Issue 10 (October 2023) , p. 2050-2061, ISSN 2472-3452

DOI: 10.1021/acsearthspacechem.3c00167
PMID: 37876665

12 p, 10.2 MB

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