TY - JOUR
T1 - CO2 reduction by a Mn electrocatalyst in the presence of a Lewis acid
T2 - A DFT study on the reaction mechanism
AU - Isegawa, Miho
AU - Sharma, Akhilesh K.
N1 - Funding Information:
This work was supported by the World Premier International Research Center Initiative (WPI) and JSPS KAKENHI grant number 18K05297. MI acknowledges the support from a Fukui Fellowship from Kyoto University. Computer resources at the Academic Center for Computing and Media Studies at Kyoto University, Research Center of Computer Science at the Institute for Molecular Science are also acknowledged.
Publisher Copyright:
© 2019 The Royal Society of Chemistry.
PY - 2019
Y1 - 2019
N2 - The addition of a Lewis acid (Mg2+) has been shown to improve the efficiency of CO2 reduction by homogeneous electrocatalysts. Recently, a CO2 reduction protocol involving a Mn electrocatalyst with a bulky bipyridine ligand [Mn(mesbpy)(CO)3 MeCN](mesbpy = 6,6′-dimesityl-2,2′-bipyridine) in the presence of Mg(OTf)2 was reported (Sampson et al., J. Am. Chem. Soc., 2016, 138, 1386-1393). However, a detailed mechanistic understanding of this reaction is lacking. Here we present the details of the reaction mechanism based on thermodynamic and kinetic data derived from density functional theory (DFT) calculations. The DFT calculations demonstrate that the primary role of Mg(OTf)2 is to stabilize a two-electron reduced Mn intermediate through Lewis pair binding. Furthermore, Mg(OTf)2 makes the reaction thermodynamically and kinetically feasible. In our presented mechanism, two molecules of CO2 and Mg(OTf)2 contribute to the C-O bond cleavage reaction. The demonstrated roles of Mg(OTf)2 in this catalytic process are important for the design of novel multimetallic catalysts for CO2 conversion under milder reaction conditions.
AB - The addition of a Lewis acid (Mg2+) has been shown to improve the efficiency of CO2 reduction by homogeneous electrocatalysts. Recently, a CO2 reduction protocol involving a Mn electrocatalyst with a bulky bipyridine ligand [Mn(mesbpy)(CO)3 MeCN](mesbpy = 6,6′-dimesityl-2,2′-bipyridine) in the presence of Mg(OTf)2 was reported (Sampson et al., J. Am. Chem. Soc., 2016, 138, 1386-1393). However, a detailed mechanistic understanding of this reaction is lacking. Here we present the details of the reaction mechanism based on thermodynamic and kinetic data derived from density functional theory (DFT) calculations. The DFT calculations demonstrate that the primary role of Mg(OTf)2 is to stabilize a two-electron reduced Mn intermediate through Lewis pair binding. Furthermore, Mg(OTf)2 makes the reaction thermodynamically and kinetically feasible. In our presented mechanism, two molecules of CO2 and Mg(OTf)2 contribute to the C-O bond cleavage reaction. The demonstrated roles of Mg(OTf)2 in this catalytic process are important for the design of novel multimetallic catalysts for CO2 conversion under milder reaction conditions.
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U2 - 10.1039/c9se00213h
DO - 10.1039/c9se00213h
M3 - Article
AN - SCOPUS:85068130117
SN - 2398-4902
VL - 3
SP - 1730
EP - 1738
JO - Sustainable Energy and Fuels
JF - Sustainable Energy and Fuels
IS - 7
ER -
