Shape-controlled Cu nanocrystals to unlock selectivity pathways in the electrochemical CO2 reduction reaction
Raffaella Buonsanti (EPFL)
ABSTRACT:
In the electrochemical CO2 reduction reaction (CO2RR) selectivity still remains an important issue.
In this talk, I will showcase a few examples which highlight how shape-controlled nanocrystals can contribute to address this challenge. First of all, I will discuss how size control of Cu nanocubes (Cucub) and Cu octahedra (Cuoh) has revealed the importance of facet-ratio to maximize the selectivity towards ethylene and methane, respectively. Second, I will present our recent computational-experimental efforts towards using well-defined NCs to elucidate selectivity rules at the hydrocarbons/alcohols branching nodes in the CO2RR pathway. The formation of ethanol via *CHx-*CO coupling or *CO-*CO coupling is an open debate in the literature. As a platform to address this question, we have used CH4 favoring (i.e. *CHx populated) Cuoh and C2H4 favoring (i.e. *CO-*CO populated) Cucub under enhanced *CO coverage induced by the presence of Ag NCs. The selective promotion of ethanol on the Cuoh provided evidence for *CHx-*CO coupling being the preferred pathway. Following theoretical predictions, we have also demonstrated that such pathway is favored on Cu(110) edge sites compared to Cu(100) terraces by studying the size-dependent edge/face ratio of the Cucub always in the presence of the CO-generating Ag domains. Indeed, we found that smaller cubes are more selective for ethanol than bigger sizes. Generally, these examples encourage the application of well-defined nano catalysts as a bridge between theory and experiments in electrocatalysis.
BIO:
Dr. Raffaella Buonsanti is a Tenure Track Assistant Professor at the Institute of Chemical Sciences and Engineering (ISIC) of the École Polytechnique Fédérale de Lausanne (EPFL) since October 2015. She received her Master Degree in Chemistry from the University of Bari in 2006. In 2010, she graduated in Chemistry from the University of Salento working at the National Nanotechnology Laboratory (NNL, in Lecce-Italy). She continued her research as a postdoc at the Molecular Foundry, the Nanoscience Research Center at Lawrence Berkeley National Laboratory (LBNL). After two years as a postdoctoral researcher, she was promoted to Project Scientist in the Molecular Foundry. Then, from 2013 to 2015, she was a tenure-track staff scientist at LBNL where she started her own research program within the Joint Center of Artificial Photosynthesis.
At EPFL, Professor Buonsanti implements a highly interdisciplinary approach, spanning from Chemistry to Materials Science and Chemical Engineering, to address fundamental challenges in energy technologies. Through the core expertise in colloidal synthesis, her team develops novel approaches to controlled and tunable nanomaterials to drive chemical transformations.