Activity and Selectivity Control in CO2 eectroreduction through Catalyst and Electrolyte Design

Abstract

The electrochemical conversion of CO2 (CO2RR) into chemicals and fuels is of industrial significance since it might lead to a more efficient storage of renewable energy while closing the carbon cycle. This talk will focus on model nanostructured plasma-activated dendrites and nanoparticle (NP) electrocatalysts (Cu, Ag, Zn, Cu-M with M = Co, Zn and Ag-Sn) for the electrocatalytic reduction of CO2. We will show how to tune catalytic selectivity based on rational catalyst and electrolyte design involving controlling the NP size, shape, support interaction, as well as the electrolyte properties by adding cations and anions (Cs+, Li+, Na+, K+, I-, Br-, Cl-). 1-5 In situ and operando spectroscopic and microscopic methods have been used to gain insight into the correlation between the structure, chemical state, and reactivity of ligand-free size- and shape-controlled spherical and cubic NPs as well as plasma-activated dendritic structures and Cu single crystals during CO2RR. Dynamic changes in the morphology and composition were monitored under potential control via electrochemical atomic force microscopy, X-ray absorption fine-structure spectroscopy and quasi in situ X-ray photoelectron spectroscopy. Additionally, density functional theory calculations were used to provide new insights on the active sites and reaction mechanism of the former electrocatalysts, including the role of different electrolytes. Our results are expected to open up new routes for the reutilization of CO2 through its direct selective conversion into higher value products. 1. P. Grosse, D. Gao, F. Scholten, I. Sinev, H. Mistry, B. Roldan Cuenya, Angewandte Chemie (2018) in press. 2. H. S. Jeon, S. Kunze, F. Scholten, B. Roldan Cuenya, ACS Catal. 8 (2018) 531 3. H. Mistry, Y. Choi, A. Bagger, F. Scholten, C. Bonifacio, I. Sinev, N. J. Divins, I. Zegkinoglou, H. Jeon, K. Kisslinger, E. A. Stach, J. C. Yang, J. Rossmeisl, B. Roldan Cuenya, Angew. Chem. 56, 11394 (2017) 4. D. Gao, F. Scholten, B. Roldan Cuenya, ACS Catal. 7, 5112 (2017) 5. D. Gao, I. Zegkinoglou, N. J. Divins, F. Scholten, I. Sinev, P. Grosse, and B. Roldan Cuenya, ACS Nano 11, 4825 (2017)