M.D. González-Hernández 1,2*, Eileen Yu2, A.P. de los Ríos1

Synthesis of electrodes for the electroreduction of

carbon dioxide

1 School of Chemical Engineering and Advanced Materials, University of Newcastle Upon Tyne, Newcastle NE1 7RU, United Kingdom 2 Department of Chemical Engineering, Faculty of Chemistry, University of Murcia, Campus de Espinardo, E-30100, Murcia, Spain

*Corresponding author. Tel.: +34 868 889 112; fax: +34 968 364 148. E-mail address: mariadelia.gonzalez@um.es

References [1] Huazhang Zhao, Yan Zhang, Bin Zhao, Yingyue Chang and Zhenshan Li, Electrochemical Reduction of Carbon Dioxide in an MFC−MEC System with a Layer-by-Layer Self-Assembly Carbon Nanotube/ Cobalt

Phthalocyanine Modified Electrode. Environmental Science and Tecnology 46 (2012) 5198−5204.

[2] M.Le, M.Ren, Z.Zhang, P.T. Sprunger, R.L. Kurtz and J.C. Flake. Gordon and Mary Cain, Electrochemical reduction of CO2 to CH3OH at copper oxide surface. Journal of the electrochemical society, 158 (2011) 45-49.

[3] Tin-Yu Chang, Ru-Meng Liang, Pu-Wei Wu, Jing-Yu Chen, Yu-Chi Hsieh, Electrochemical reduction of CO2 by Cu2O catalysed carbon cothes. Materials Letters 63 (2009) 1001-1003.

Introduction

Materials and Methods

The CO2 could be considered as an almost infinite source of carbon for chemical industry in the production of alcohols, aldehydes, hydrocarbons

or carboxylic acids. However, only 1% of entire atmospheric CO2 is used for chemical synthesis. Mainly this is due to its high chemical

inertness and the difficulties associated with its capture. Despite these, many scientists are working to convert greenhouse gasses into

commercially valuable compounds since this could make removal of excess CO2 from the atmosphere into a profitable industry.

For that reason the electrocatalytic reduction of CO2 to liquid fuels, chemical feedstock and valuable chemicals has attracted growing

interest in CO2 capture in the past several years. These electrochemical processes offer good reaction selectivity and reduced cost because of

possibility of direct control of electrode surface free energy through electrode potential.

For this research project we studied the synthesis of catalysts for CO2 electroreduction to methanol, all of them based on cuprous oxide (Cu2O)

modified surface because this compound has previously shown specific catalytic activity for this electrochemical reaction. The same project also

focused on developing a catalyst for CO2 electroreduction to formic acid. For this purpose a metallic complex was synthesized belonging to the

aminoftalocianes group which contain metals known to have good catalytic activity for CO2 electroreduction [2,3].

Conclusions THE PRESENCE OF METHANOL WAS DETECTED IN ALL CUPROUS OXIDE ELECTRODES. THE NEXT TARGET IS TO INCREASE METHANOL AND

FORMIC ACID YIELD. FURTHERMORE, A FUTURE AIM IS TO USE MICROBIAL FUEL CELLS (MFCS) AS ENERGY SOURCES [1].

EXPERIMENTAL SET-UP

CONVERSION TO METHANOL: CONVERSION TO FORMIC ACID:

ELECTRODES TO ELECTROCHEMICAL

REDUCTION OF CO2

Results and Discussion

1Copper electrode covered with cuprous oxide film

electrochemically obtained

2Stainless steel mesh electrode with electrodeposited

cuprous oxide.

3Carbon paper electrode impregnated with cuprous

oxide nanoparticles.

1 2 3

4Chemical formula

(2,9,16,23-tetraamine-phthalocyanine cobalt) 5Synthesised complex solid

4

5

6Glassy carbon covered with

2,9,16,23-tetraamine-phthalocyanine

polymeric film

6

7Typical electrocatalytic cell used in

most of the experiments.

8Electrocatalytic cell with Cu2O

nanoparticles-impregnated carbon

paper electrode.

7 8

All Synthesized electrodes have been studied by cyclic voltammetry in nitrogen and carbon dioxide saturated solutions.

Cuprous oxide electrodes had their surface analysed by SEM (scanning electron microscope).

Regarding to the stainless steel mesh electrode with electrodeposited cuprous oxide these are the results.

SEM IMAGE OF THE ELECTRODE: FORMIC ACID YIELD: METHANOL YIELD:

USED CELLS:

You can see the presence of the crystalline

structures of Cu2O agglomerates. The SEM

image shows catalytic presence on the

electrode surface.

The results from spectrophotometer show that the

methanol yield was 43,167 ppm of CH3OH. The results from ion

chromatograph shows that the

formic acid yield was

3,643 ppm of HCOOH.

0,0259 = 0,0006 ∗ 𝐶𝐻3𝑂𝐻 ;

𝐶𝐻3𝑂𝐻 = 43,167 ppm

0,051 = 0,0006 ∗ 𝐶𝐻3𝑂𝐻 ;

𝐻𝐶𝑂𝑂𝐻 = 3,643 ppm