Electrochemical CO2 Reduction at Glassy Carbon Electrodes Functionalized by MnI and ReI Organometallic Complexes

Cunfa Sun; Laura Rotundo; Claudio Garino; Luca Nencini; Sam S Yoon; Roberto Gobetto; Carlo Nervi

doi:10.1002/cphc.201700739

Electrochemical CO₂ Reduction at Glassy Carbon Electrodes Functionalized by Mn^I and Re^I Organometallic Complexes

Chemphyschem. 2017 Nov 17;18(22):3219-3229. doi: 10.1002/cphc.201700739. Epub 2017 Aug 18.

Authors

Cunfa Sun^{1

2

3}, Laura Rotundo^{1

2}, Claudio Garino^{1

2}, Luca Nencini^{1

2}, Sam S Yoon⁴, Roberto Gobetto^{1

2}, Carlo Nervi^{1

2}

Affiliations

¹ Department of Chemistry and NIS (Centre of excellence), University of Torino, via P. Giuria 7, 10125, Torino, Italy.
² CIRCC (Centro Interuniveristario di Reattività Chimica e Catalisi), Via Celso Ulpiani 27, 70126, Bari, Italy.
³ Collaborative Innovation Center of Chemistry for Energy Materials, Xiamen University, Xiamen, 361005, China.
⁴ School of Mechanical Engineering, Korea University, Seoul, 136-713, Republic of Korea.

PMID: 28834058
DOI: 10.1002/cphc.201700739

Abstract

The catalytic activities towards electrochemical CO₂ reduction of two new rhenium and manganese complexes, namely fac-Mn(apbpy)(CO)₃ Br (1) and fac-Re(apbpy)(CO)₃ Cl (2) (apbpy=4-(4-aminophenyl)-2,2'-bipyridine), in both homogeneous and heterogeneous phases are compared. A glassy carbon electrode (GCE) surface has been functionalized with complexes 1 and 2 by two approaches: a) direct electrochemical oxidation of the amino group with formation of C-N bonds, and b) electrochemical reduction of the corresponding diazonium salts with formation of C-C bonds. The chemically modified GCEs show efficient conversion of CO₂ into CO, with turnover numbers (TONs) about 60 times higher than those of the corresponding catalysts in homogeneous solutions, and in a much shorter time.

Keywords: Mn complexes; Re complexes; carbon dioxide; electrode functionalization; reduction.