Abstract
Electrodeposition of Cu, Cu/Ag, and Cu/Sn alloy films by using 3,5-diamino-1,2,4-triazole (DAT) as an electrodeposition inhibitor yields a high surface area Cu-based catalyst. All three Cu-based electrodes exhibit high Faradaic efficiency (FE) of CO2 reduction toward C2H4 production. The CuSn-DAT electrode exhibits the highest FE for CO (∼90% at -0.4 V) and C2H4 (∼60% at -0.8 V) production and high current density (∼-225 mA/cm2 at -0.8 V). In situ surface enhanced Raman spectroscopy (SERS) studies in a flow cell obtained from the three Cu-based samples show a correlation between the decreased oxide content on the Cu surface, increased presence of CO, and increased activity for CO and C2 production. The CuSn-DAT electrode has the lowest amount of Cu2O and exhibits the highest activity, whereas the Cu-DAT electrode has an increasing Cu2O content and exhibits lower activity as the potential is made negative. These results demonstrate that incorporation of different well-mixed alloy materials provides a way to tune CO2 reduction speciation.
Original language | English |
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Pages (from-to) | 672-682 |
Number of pages | 11 |
Journal | ACS Catalysis |
Volume | 10 |
Issue number | 1 |
DOIs | |
State | Published - Jan 3 2020 |
Externally published | Yes |
Funding
The authors gratefully acknowledge the support of the International Institute for Carbon Neutral Energy Research (WPI-I2CNER), sponsored by the Japanese Ministry of Education, Culture, Sports, Science and Technology. D.A.H. gratefully acknowledges Shell’s New Energy Research and Technology (NERT) program for providing funding. A.I.F. acknowledges support of the U.S. DOE Grant No. DE-FG02-03ER15476. We thank Dr. Richard T. Haasch for performing XPS and the SCS machine shop (in particular Michael A. Harland) for their help in designing the in situ flow cell for the SERS measurements. We also thank the SCS NMR lab (Dr. Dean Olsen and Dr. Lingyang Zhu) for their help in NMR measurements.
Keywords
- CO reduction
- Raman
- copper-alloy
- cupric oxide
- ethylene