Operando evidence on the chirality-enhanced oxygen evolution reaction in intrinsically chiral electrocatalysts

<p><span>Additional raw data files for manuscript&nbsp; </span>"Operando evidence on the chirality-enhanced oxygen evolution reaction in intrinsically chiral electrocatalysts"</p> <p>Felipe A. Garc&iacute;a-Pineda, a Jiahao Yu,a Camilo A. Mesa,b Sergi Plana-Ruiz,c Daniel Ruano,c<br>Yunchang Liang,d Magal&iacute; Lingenfelder,d;e Sixto Gim&eacute;nez,b and J. R. Galan-Mascaros, a; f</p> <p>Abstract:<br>Electrolytic hydrogen is identified as a crucial component in the desired decarbonisation of the chemical<br>industry, utilizing renewable energy to split water into hydrogen and oxygen. Water electrolysis<br>still requires important scientific advances to improve its performance and lower its costs. One of the<br>bottlenecks in this direction relates to the sluggish anodic oxygen evolution reaction (OER). Producing<br>anodes with competitive performance remains challenging due to the high energy loses and the<br>harsh working conditions typically imposed by this complex oxidation process. Recent advancements<br>point to spin polarization as an opportunity to enhance the kinetics of this spin-restricted reaction,<br>yielding the paramagnetic O2 molecule. One powerful strategy deals with the generation of chiral<br>catalytic surfaces, typically by surface functionalisation with chiral organic molecules, to promote<br>chiral-induced spin selectivity (CISS) effect during electron transfer. However, the relationship between<br>chirality and enhanced electrocatalysis has been established only from indirect experimental<br>evidences. In this work, we have exploited operando electrochemical and spectroscopic tools to confirm<br>the direct relationship between the faster OER kinetics and the optical activity of enantiopure<br>Fe-Ni metal oxides when compared with their achiral catalysts in alkaline conditions. Our results<br>show the participation of chiral species as reactive intermediates during the electrocatalytic reaction,<br>supporting the appearance of a mechanistic CISS enhancement. Furthermore, these intrinsically chiral<br>transition-metal oxides maintain their enhanced activity in full cell electrolyser architectures at<br>industrially relevant current densities.</p> <p>of Science and Technology (BIST), Av. Paisos Catalans 16, Tarragona, 43007, Spain<br>E-mail: fgarces@iciq.es; jrgalan@iciq.es<br>b Institute of Advanced Materials (INAM), Castell&oacute;, Spain, Universitat Jaume I, Av. de<br>Vicente Sos Baynat, Castell&oacute; 12006, Spain<br>c SRCIT-Universitat Rovira i Virgili, Avinguda Pa&uml;&otilde;sos Catalans 26, Tarragona, 43007,<br>Spain<br>d Max Planck-EPFL Laboratory for Molecular Nanoscience and Technology, &Eacute;cole Polytechnique<br>F&eacute;d&eacute;rale de Lausanne (EPFL), Lausanne, 1015, Switzerland<br>e Helvetia Institute for Science and Innovation, Wollerau, 8832, Switzerland<br>f ICREA, Passeig Lluis Companys, 23, Barcelona, 08010, Spain<br><br></p>