Scanning Flow Cell SFC SFC-OLEMS Summary CO2 reduction on Cu-Co thin films Summary

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1 Electrochemical CO2 Reduction Product Distribution Screening on Cu-Co Thin Film Composition Spread Samples by Coupling of a Scanning Flow Cell to OLEMS Department of Interface Chemistry and Surface Engineering Electrocatalysis Group Düsseldorf, Germany Jan Philipp Grote, Aleksandar R. Zeradjanin, Serhiy Cherevko, Karl J.J. Mayrhofer grote@mpie.de DEMS Workshop, Patras Scanning Flow Cell Reference electrode Counter electrode Electrolyte supply Electrolyte outlet Ar Ar Silicon sealing Working electrode 2mm Channel diameter: 0.2/0.4/1/3 mm Flow rate: μl/min CE: Pt-wire or C-rod WE area: 0.13/0.25/1.1/10mm 2 RE: Ag/AgCl/3M KCl 1

2 Online Electrochemical Mass Spectrometer Good sensitivity Flexibility in electrode choice A. H. Wonders, T. H. M. Housmans, V. Rosca, and M. T. M. Koper, J. Appl. Electrochem., 36, (2006) SFC-Online Electrochemical Mass Spectrometer Stability 1.2mm PEEK Selectivity 0.5mm PTFE 0.8mm Teflon membrane 20 nm pore size J.-P. Grote, A. R. Zeradjanin, S. Cherevko, and K. J. J. Mayrhofer, Rev. Sci. Instrum., 85, (2014) 2

3 SFC-OLEMS SFC-OLEMS 3

4 SFC-OLEMS SFC-OLEMS fused silica capillary Inner diameter: 530µm 4

5 H 2 Evolution/Calibration 29 Copper 63, M KHCO 3, ph = 9.5 Argon saturated Flow rate: 0.12 ml/min Flow speed: 1.84 cm/min Detection limit: 0.8 ma cm -2 J.-P. Grote, A. R. Zeradjanin, S. Cherevko, and K. J. J. Mayrhofer, Rev. Sci. Instrum., 85, (2014) Reproducibility / CO 2 Reduction Reproducibility CO 2 Reduction Scan rate: 10 mv s Copper 63, M KHCO 3, ph = 9.5 Argon saturated 29 Copper 63, M KHCO 3, ph = 7.3 CO 2 saturated J.-P. Grote, A. R. Zeradjanin, S. Cherevko, and K. J. J. Mayrhofer, Rev. Sci. Instrum., 85, (2014) 5

6 Summary SFC-OLEMS Combination of product analysis ability of OLEMS with screening capability of SFC Flexibility in choice of electrodes: Bulk samples, thin films, high surface area catalysts Semi-quantitative results Sufficient response time ( 2-3 sec) and sensitivity Tested for CO 2 reduction, Mg corrosion, carbon corrosion and isotope labled OER Electrochemical CO 2 Reduction on Cu-Co Thin Film Composition Spread Samples 6

7 CO 2 Reduction Pd, Hg, In, Sn, Cd, Tl, Bi HCOO - Au, Ag, Zn CO CO 2 Cu Hydrocarbons Ni,Fe, Pt, Ti, Ga, Co H 2 "Carbon cycle" by Diagram adapted from U.S. DOE, Biological and Environmental Research Information System. - Scaling Relations H 2 O CH 4 H 2 O CO 2 COOH CO CHO CH 2 O OCH 3 O OH Peterson, A. A., & Nørskov, J. K. (2012). Activity Descriptors for CO 2 Electroreduction to Methane on Transition-Metal Catalysts. The Journal of Physical Chemistry Letters, 3(2), doi: /jz201461p 7

8 Scaling Relations H 2 O CH 4 H 2 O CO 2 COOH CO CHO CH 2 O OCH 3 O OH Peterson, A. A., & Nørskov, J. K. (2012). Activity Descriptors for CO 2 Electroreduction to Methane on Transition-Metal Catalysts. The Journal of Physical Chemistry Letters, 3(2), doi: /jz201461p Breaking Scaling Relations Peterson, A. A., & Nørskov, J. K. (2012). Activity Descriptors for CO 2 Electroreduction to Methane on Transition-Metal Catalysts. The Journal of Physical Chemistry Letters, 3(2), doi: /jz201461p 8

9 SFC - Fast Screening of Alloys Prof. Ludwig, Ruhr-Universität Bochum, Institute of Materials, Faculty of Mechanical Engineering SFC - Fast Screening of Alloys Prof. Ludwig, Ruhr-Universität Bochum, Institute of Materials, Faculty of Mechanical Engineering 9

10 Fragments Fragments 10

11 Measurement Procedure Galvanostatic product distribution 11

12 Potentiostatic product distribution Cyclic voltammetry 12

13 Change in reaction mechanism? Suggested change in reaction mechanism: Change from CHO to COH intermediate Improved CO-CO dimer formation Mixing Cu with Co can shift selectivity towards C2 products while overpotential is slightly reduced Change in intermediate product from CHO to COH or improved CO- CO dimer formation might lead to shif towards C 2 products Tranfer of the results to nanstructured surfaces of GDE Summary Cu-Co Influence of cobalt on pre oxidized and electrochemical reduced electrodes 13

14 Thanks for your attention! Electrocatalysis Group from Max-Planck-Institut für Eisenforschung 14