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

Additional raw data files for manuscript  "Operando evidence on the chirality-enhanced oxygen evolution reaction in intrinsically chiral electrocatalysts"

Felipe A. García-Pineda, a Jiahao Yu,a Camilo A. Mesa,b Sergi Plana-Ruiz,c Daniel Ruano,cYunchang Liang,d Magalí Lingenfelder,d;e Sixto Giménez,b and J. R. Galan-Mascaros, a; f

Abstract:Electrolytic hydrogen is identified as a crucial component in the desired decarbonisation of the chemicalindustry, utilizing renewable energy to split water into hydrogen and oxygen. Water electrolysisstill requires important scientific advances to improve its performance and lower its costs. One of thebottlenecks in this direction relates to the sluggish anodic oxygen evolution reaction (OER). Producinganodes with competitive performance remains challenging due to the high energy loses and theharsh working conditions typically imposed by this complex oxidation process. Recent advancementspoint to spin polarization as an opportunity to enhance the kinetics of this spin-restricted reaction,yielding the paramagnetic O2 molecule. One powerful strategy deals with the generation of chiralcatalytic surfaces, typically by surface functionalisation with chiral organic molecules, to promotechiral-induced spin selectivity (CISS) effect during electron transfer. However, the relationship betweenchirality and enhanced electrocatalysis has been established only from indirect experimentalevidences. In this work, we have exploited operando electrochemical and spectroscopic tools to confirmthe direct relationship between the faster OER kinetics and the optical activity of enantiopureFe-Ni metal oxides when compared with their achiral catalysts in alkaline conditions. Our resultsshow the participation of chiral species as reactive intermediates during the electrocatalytic reaction,supporting the appearance of a mechanistic CISS enhancement. Furthermore, these intrinsically chiraltransition-metal oxides maintain their enhanced activity in full cell electrolyser architectures atindustrially relevant current densities.

of Science and Technology (BIST), Av. Paisos Catalans 16, Tarragona, 43007, SpainE-mail: [e-mail]; [e-mail] Institute of Advanced Materials (INAM), Castelló, Spain, Universitat Jaume I, Av. deVicente Sos Baynat, Castelló 12006, Spainc SRCIT-Universitat Rovira i Virgili, Avinguda Pa¨õsos Catalans 26, Tarragona, 43007,Spaind Max Planck-EPFL Laboratory for Molecular Nanoscience and Technology, École PolytechniqueFédérale de Lausanne (EPFL), Lausanne, 1015, Switzerlande Helvetia Institute for Science and Innovation, Wollerau, 8832, Switzerlandf ICREA, Passeig Lluis Companys, 23, Barcelona, 08010, Spain