CO2 reduction by a Mn electrocatalyst in the presence of a Lewis acid: A DFT study on the reaction mechanism

Miho Isegawa, Akhilesh K. Sharma

Research output: Contribution to journalArticle

Abstract

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.

Original languageEnglish
Pages (from-to)1730-1738
Number of pages9
JournalSustainable Energy and Fuels
Volume3
Issue number7
DOIs
Publication statusPublished - Jan 1 2019

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Electrocatalysts
Density functional theory
Acids
Ligands
Thermodynamics
Catalysts
Molecules
Kinetics
Electrons

All Science Journal Classification (ASJC) codes

  • Renewable Energy, Sustainability and the Environment
  • Fuel Technology
  • Energy Engineering and Power Technology

Cite this

CO2 reduction by a Mn electrocatalyst in the presence of a Lewis acid : A DFT study on the reaction mechanism. / Isegawa, Miho; Sharma, Akhilesh K.

In: Sustainable Energy and Fuels, Vol. 3, No. 7, 01.01.2019, p. 1730-1738.

Research output: Contribution to journalArticle

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