@misc{10481/55402,
year = {2018},
month = {5},
url = {http://hdl.handle.net/10481/55402},
abstract = {One of the most promising strategies for the safe and permanent disposal of anthropogenic
CO2 is its conversion into carbonate minerals via the carbonation of calcium and magnesium silicates.
However, the mechanism of such a reaction is not well constrained, and its slow kinetics is a
handicap for the implementation of silicate mineral carbonation as an effective method for CO2
capture and storage (CCS). Here, we studied the different steps of wollastonite (CaSiO3) carbonation
(silicate dissolution -> carbonate precipitation) as a model CCS system for the screening of natural
and biomimetic catalysts for this reaction. Tested catalysts included carbonic anhydrase (CA),
a natural enzyme that catalyzes the reversible hydration of CO2(aq), and biomimetic metal-organic
frameworks (MOFs). Our results show that dissolution is the rate-limiting step for wollastonite
carbonation. The overall reaction progresses anisotropically along different [hkl] directions via a
pseudomorphic interface-coupled dissolution–precipitation mechanism, leading to partial passivation
via secondary surface precipitation of amorphous silica and calcite, which in both cases is anisotropic
(i.e., (hkl)-specific). CA accelerates the final carbonate precipitation step but hinders the overall
carbonation of wollastonite. Remarkably, one of the tested Zr-based MOFs accelerates the dissolution
of the silicate. The use of MOFs for enhanced silicate dissolution alone or in combination with other
natural or biomimetic catalysts for accelerated carbonation could represent a potentially effective
strategy for enhanced mineral CCS.},
organization = {This research was funded by the Spanish Government (grants CGL2015-70642-R,
CGL2015-73103-EXP, CTQ2017-84692-R), EU FEDER funding, the University of Granada (“Unidad Científica de
Excelencia” UCE-PP2016-05) and the Junta de Andalucía (grant P11-RNM-7550 and Research Group RNM-179).
We thank the personnel of the Centro de Instrumentación Científica (CIC) of the University of Granada for their
help during TG-DSC, FESEM,  -XRD, and ICP-OES analyses.},
publisher = {MDPI},
keywords = {Carbonation},
keywords = {Wollastonite},
keywords = {Catalysts},
keywords = {Carbonic anhydrase},
keywords = {MOFs},
keywords = {Carbon capture and storage},
title = {The Carbonation of Wollastonite: A Model Reaction to Test Natural and Biomimetic Catalysts for Enhanced CO2 Sequestration},
author = {Lorenzo, Fulvio Di and Ruiz Agudo, Cristina and Ibáñez Velasco, Aurelia María and Gil San Millán, Rodrigo and Navarro, Jorge A. R. and Ruiz-Agudo, Encarnacion and Rodríguez Navarro, Carlos Manuel},
}