THE CITY COLLEGE OF NEW YORK
CHEMICAL ENGINEERING DEPARTMENT
Professor Daniel Esposito
Monday, February 5, 2018
Seminar will be held in MR-1307 (Marshak Building) at 2:00 PM
Reception will be held in Steinman Hall, Exhibit Room – 1st Floor
From 3:00 – 3:30 PM
Hydrogen Evolution at Buried Interfaces
Electrocatalysis underlies many clean energy technologies, such as fuel cells and electrolyzers, which are expected to be key components of a sustainable energy future. However, continued improvements in electrocatalyst activity, durability, and selectivity must be achieved in order to make this future a reality. In this study, we explore the use of electrocatalyst architectures based on metallic electrocatalysts that have been encapsulated by ultra-thin overlayers made of silicon dioxide (glass). These oxide layers are synthesized with a room temperature process and deposited as uniform and continuous layers onto thin films of Pt, one of the most commonly used electrocatalyst materials. Through a series of electroanalytical measurements, we show that these oxide overlayers can be selectively permeable to certain electroactive species and thereby enable efficient and selective electrocatalysis at the buried interface between the oxide overlayer and active catalyst. By systematically varying the thickness of the oxide overlayer, we explore its transport properties and influence on the performance of thin film hydrogen evolution and alcohol oxidation electrocatalysts. Importantly, this work highlights the potential of oxide-encapsulated electrocatalysts to serve as a tunable platform for efficient and stable electrocatalysis of a variety of electrochemical reactions.
Daniel Esposito received his Ph.D. in Chemical Engineering at the University of Delaware and studied as a postdoctoral research associate at the National Institute of Standards and Technology (NIST) under a National Research Council fellowship. He is now an Assistant Professor in Chemical Engineering at Columbia University, where his group’s research interests relate broadly to solar and electrochemical energy conversion. Specific topics of interest including electrocatalysis, photoelectrochemistry, membrane-free electrochemical devices, and the use of in situ analytical tools for studying electrocatalytic materials at high spatial and/or temporal resolution. At Columbia, his research group combines expertise in electrochemical fundamentals with core Chemical Engineering principles to develop unconventional (photo)electrocatalytic materials and devices.
 N. Y. Labrador, X. Li, Y. Liu, J. T. Koberstein, R. Wang, H. Tan, T. P. Moffat, and D. V. Esposito, “Enhanced Performance of Si MIS Photocathodes Containing Oxide-Coated Nanoparticle Electrocatalysts” , Nano Letters, vol. 16, 6452-6459, 2016.
 D.V. Esposito, “Membrane Coated Electrocatalysts—an Alternative Approach to Achieving Stable and Tunable Electrocatalysis“, ACS Catalysis, 2018, vol. 8, pp 457–465.
 N. Y. Labrador, E. L. Songcuan, C. De Silva, Han Chen, Sophia Kurdziel, Ranjith K. Ramachandran, Christophe Detavernier, D.V. Esposito, “Hydrogen Evolution at the Buried Interface between Pt Thin Films and Silicon Oxide Nanomembranes”. ACS Catalysis (Accepted