Speaker
Description
Electrochemical energy conversion driven by renewable energy is a cost-effective, environmentally friendly route to convert undesired substances (such as CO2) into valuable chemicals and fuels, but a suitable catalyst is needed. Here, Cu-based catalysts are particularly attractive due to their unique ability to convert CO2 into more complex hydrocarbons [1]. A challenge for the practical application of complex electrochemical processes as the CO2 electrocatalytic reduction reaction (CO2RR) is however the selectivity control. Convoluted selectivity trends and a missing link between reaction product distribution and the catalyst properties hinder practical applications of the CO2RR for multi-carbon product generation [2,3].
One of the critical parameters affecting the catalyst’s properties and function - its oxidation state - can be conveniently manipulated in situ by choosing appropriate applied potentials [4]. In particular, under pulsed reaction conditions, where pulses of a working (cathodic) potential are intermitted with short pulses of anodic potential, the desired structural motifs and preferred oxidation state can be (re-)generated [5,6]. Here, we steer the CO2RR selectivity of a Cu2O nanocube-derived catalyst by varying the type and amount of copper oxide formed during the restoring pulses. In particular, ethanol formation is doubled, as compared to stationary conditions, within a narrow range of pulse durations, where a balance between metallic Cu and distorted copper oxide species is achieved on the catalyst surface. The latter was revealed by time-resolved operando X-ray absorption spectroscopy (XAS), high energy X-ray diffraction (XRD), and quasi-in situ X-ray photoelectron spectroscopy (XPS). Our study demonstrates the great prospect of pulsed electrolysis for tailoring the catalyst performance, and highlights the role of operando investigations for the mechanistic understanding of a new generation of catalysts operating under dynamically changing reaction conditions [7].
References
1. Y. Hori, K. Kikuchi, S. Suzuki, Chem. Lett. 14, 1695 (1985).
2. H. Mistry, A.S. Varela, S. Kuehl, P. Strasser, B. Roldan Cuenya, Nat. Reviews Materials. 1, 16009 (2016).
3. D. Gao, I. R.M. Arán-Ais, H.S. Jeon, B. Roldan Cuenya, Nat. Catalysis 2, 198, (2019).
4. H. Mistry, A.S. Varela, C.S. Bonifacio, I. Zegkinoglou, I. Sinev, Y.W. Choi, K. Kisslinger, E.A. Stach, J. C. Yang, P. Strasser, B. Roldan Cuenya, Nat. Commun. 7, 12123 (2016).
5. R.M. Arán-Ais, F. Scholten, S. Kunze, R. Rizo, B. Roldan Cuenya, Nat. Energy 5, 317 (2020).
6. H.S. Jeon, J. Timoshenko, C. Rettenmaier, A. Herzog, A. Yoon, S.W. Chee, S. Oener, U. Hejral, F.T. Haase, B. Roldan Cuenya, J. Am. Chem. Soc. 143, 7578 (2021).
7. J. Timoshenko, A. Bergmann, C. Rettenmaier, A. Herzog, R. M. Arán-Ais, H. S. Jeon, F. T. Haase, U. Hejral, P. Grosse, S. Kühl, E. M. Davis, J. Tian, O. Magnussen, B. Roldan Cuenya, Nature Catal. 5, 259 (2022).
| Abstract Number (department-wise) | ISC 04 |
|---|---|
| Department | ISC (Roldán) |
