Hydroxyapatite-based biphasic catalysts with plasticity properties and its potential in carbon dioxide fixation

The design of catalysts with controlled selectivity at will, also known as catalytic plasticity, is a very attractive approach for the recycling of carbon dioxide (CO2). In this work, we study how catalytically active hydroxyapatite (HAp) and brushite (Bru) interact synergistically, allowing the pro...

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Detalles Bibliográficos
Autores: Sans Milà, Jordi|||0000-0002-2756-0492, Arnau Roca, Marc|||0000-0001-6038-3902, Sanz, Vanesa, Turon, Pau, Alemán Llansó, Carlos|||0000-0003-4462-6075
Tipo de recurso: artículo
Fecha de publicación:2022
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/367739
Acceso en línea:https://hdl.handle.net/2117/367739
https://dx.doi.org/10.1016/j.cej.2021.133512
Access Level:acceso abierto
Palabra clave:Chemical engineering
Calcium phosphate
CO2 reduction
Ethanol production
Heterogeneous catalysis
Polarized hydroxyapatite
Enginyeria química
Àrees temàtiques de la UPC::Enginyeria química
Descripción
Sumario:The design of catalysts with controlled selectivity at will, also known as catalytic plasticity, is a very attractive approach for the recycling of carbon dioxide (CO2). In this work, we study how catalytically active hydroxyapatite (HAp) and brushite (Bru) interact synergistically, allowing the production of formic acid or acetic acid depending on the HAp/Bru ratio in the catalyst. Raman, wide angle X-ray scattering, X-ray photoelectron spectroscopy, scanning electron microscopy and electrochemical impedance spectroscopy studies, combined with an exhaustive revision of the crystalline structure of the catalyst at the atomic level, allowed to discern how the Bru phase can be generated and stabilized at high temperatures. Results clearly indicate that the presence of OH– groups to maintain the crystalline structural integrity in conjunction with Ca2+ ions less bonded to the lattice fixate carbon into C1, C2 and C3 molecules from CO2 and allow the evolution from formic to acetic acid and acetone. In this way, the plasticity of the HAp-Bru system is demonstrated, representing a promising green alternative to the conventional metal-based electrocatalysts used for CO2 fixation. Thus, the fact that no electric voltage is necessary for the CO2 reduction has a very favorable impact in the final energetic net balance of the carbon fixation reaction.