BEGIN:VCALENDAR VERSION:2.0 PRODID:Icfo X-PUBLISHED-TTL:P1W BEGIN:VEVENT UID:6ae6b7aa73ffa DTSTART:20261102T090000Z SEQUENCE:0 TRANSP:OPAQUE LOCATION:Auditorium SUMMARY:ICFO | APARNA M. DAS CLASS:PUBLIC DESCRIPTION:Rising atmospheric CO2 levels\, driven primarily by anthropogen ic emissions\, are a central contributor to global climate change and envi ronmental instability. Electrocatalytic reactions provide a promising path way for CO2 emission reduction through electricity-driven conversion of CO 2 and/or water into value-added chemicals and fuels. In this context\, cat alysts are widely recognized as the key determinants of performance. This thesis takes the discussion a step further by examining how\, in specific reactions\, not only the catalyst itself but also the surrounding environm ent becomes crucial in defining performance matrices. More specifically\, it investigates dynamic catalyst-electrolyte interfaces in water electroly sis and direct bicarbonate reduction\, with a particular emphasis on inter facial dynamics and their correlation with activity.\nThe thesis first out lines the fundamental aspects of water electrolysis and bicarbonate reduct ion\, and then presents new concepts and findings on the role of dynamic c atalyst-electrolyte interfaces in these systems. To do so\, several in sit u and operando techniques are employed\, including Raman spectroscopy\, X- ray absorption spectroscopy\, electrochemical impedance spectroscopy\, and quantitative bubble analysis\, complemented by other electrochemical meth ods to establish correlations with performance.\nIn the case of water elec trolysis\, the thesis focus on the oxygen evolution reaction\, which repre sents the largest energetic penalty in the system. Correlations spanning a tomic to microscale features are identified\, collectively shaping the per formance landscape of the reaction. Using complementary in situ probes\, t hese correlations are shown to go beyond simple cause-and-effect relations hips\, highlighting the importance of uncovering the underlying mechanisms rather than relying solely on performance metrics.\nIn direct bicarbonate reduction\, performance is strongly influenced by the availability of CO2 at the interface\, which is in turn linked to the local pH. Through opera ndo Raman spectroscopy\, a descriptor for the interfacial buffering state is identified\, providing indirect insight into instantaneous CO2 availabi lity. This hypothesis is further validated by engineering the catalyst-ele ctrolyte interface to actively tune this descriptor\, resulting in a three fold improvement in performance. This demonstrates how mechanistic underst anding of the catalyst-electrolyte interface can guide informed hypotheses that are ultimately deterministic\, reducing the experimental parameter s pace and improving optimization efficiency.\nOverall\, the thesis emphasiz es the importance of understanding why performance improves\, rather than simply attributing progress to &ldquo\;better catalysts&rdquo\;. A deeper understanding of these systems\, especially at high current densities\, ca n lead to more coherent design principles and challenge existing assumptio ns about major factors governing the electrochemical performance. The resu lts show that the catalyst surface cannot be considered a static entity\, but rather a dynamic system whose structure and reactivity are continuousl y modulated by external factors. These insights provide a more detailed me chanistic picture of electrochemical interfaces and help identify key desc riptors for catalyst design. DTSTAMP:20261101T035314Z END:VEVENT END:VCALENDAR