TY - JOUR
T1 - Carbon Capture by Metal Oxides
T2 - Unleashing the Potential of the (111) Facet
AU - Mutch, Greg A.
AU - Shulda, Sarah
AU - McCue, Alan J.
AU - Menart, Martin J.
AU - Ciobanu, Cristian V.
AU - Ngo, Chilan
AU - Anderson, James A.
AU - Richards, Ryan M.
AU - Vega-Maza, David
N1 - This work was supported by the Engineering and Physical Sciences Research Council (EPSRC) via a Doctoral Training Grant for G.A.M. (EP/K0502960/1) and a Doctoral Prize Fellowship (EP/M50791X/1). Dedicated to the memory of Kenneth J. Klabunde.
Supporting Information. Synthesis procedure, experimental methods, computational methods, transmission microscopy images, N2 adsorption-desorption isotherms and pore size distributions, additional CO2 adsorption isotherms and density functional theory model surfaces. This material is available free of charge via the Internet at http://pubs.acs.org.
PY - 2018/4/4
Y1 - 2018/4/4
N2 - Solid metal oxides for carbon capture exhibit reduced adsorption capacity following high-temperature exposure, due to surface area reduction by sintering. Furthermore, only low-coordinate corner/edge sites on the thermodynamically stable (100) facet display favorable binding toward CO2, providing inherently low capacity. The (111) facet, however, exhibits a high concentration of low-coordinate sites. In this work, MgO(111) nanosheets displayed high capacity for CO2, as well as a ∼65% increase in capacity despite a ∼30% reduction in surface area following sintering (0.77 mmol g–1 @ 227 m2 g–1 vs 1.28 mmol g–1 @ 154 m2 g–1). These results, unique to MgO(111), suggest intrinsic differences in the effects of sintering on basic site retention. Spectroscopic and computational investigations provided a new structure–activity insight: the importance of high-temperature activation to unleash the capacity of the polar (111) facet of MgO. In summary, we present the first example of a faceted sorbent for carbon capture and challenge the assumption that sintering is necessarily a negative process; here we leverage high-temperature conditions for facet-dependent surface activation.
AB - Solid metal oxides for carbon capture exhibit reduced adsorption capacity following high-temperature exposure, due to surface area reduction by sintering. Furthermore, only low-coordinate corner/edge sites on the thermodynamically stable (100) facet display favorable binding toward CO2, providing inherently low capacity. The (111) facet, however, exhibits a high concentration of low-coordinate sites. In this work, MgO(111) nanosheets displayed high capacity for CO2, as well as a ∼65% increase in capacity despite a ∼30% reduction in surface area following sintering (0.77 mmol g–1 @ 227 m2 g–1 vs 1.28 mmol g–1 @ 154 m2 g–1). These results, unique to MgO(111), suggest intrinsic differences in the effects of sintering on basic site retention. Spectroscopic and computational investigations provided a new structure–activity insight: the importance of high-temperature activation to unleash the capacity of the polar (111) facet of MgO. In summary, we present the first example of a faceted sorbent for carbon capture and challenge the assumption that sintering is necessarily a negative process; here we leverage high-temperature conditions for facet-dependent surface activation.
U2 - 10.1021/jacs.8b01845
DO - 10.1021/jacs.8b01845
M3 - Article
VL - 140
SP - 4736
EP - 4742
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 13
ER -