Loading Events

« All Events

  • This event has passed.

Platinum: Not as Noble as We Thought

February 2, 2022 @ 12:00 pm - 1:00 pm

ChE Seminar Series Presents:

Arthur Shih, Ph.D.

Leiden Institute of Chemistry, Leiden University, The Netherlands

Abstract

Understanding of catalysis at a fundamental level has historically lagged behind its commercial counterpart with the Haber-Bosch ammonia synthesis process and catalytic converters as pertinent examples [1]. This historical paradigm, however, is shifting with the advancement of computing prowess and collaboration. We will discuss how experiments and density functional theory (DFT) computations led us to discover that platinum, a noble metal that is frequently utilized as a catalyst in the cathode of fuel cells, restructures when the voltage is held constant between fuel-cell relevant voltages of 0.6 and 1.0 V on a reversible hydrogen electrode scale (VRHE) [2].

An anomalous reduction feature at ~0.53 VRHE was observed on a Pt(111) single crystal in Ar-saturated HClO4 after holding at the fuel-cell relevant voltage of 0.8 VRHE (Figure 1). Decades of research has established that Pt(111) in HClO4 oxidizes H2O to adsorbed *OH between 0.6 and 1.0 VRHE [3-5] and this current model is unable to explain the anomalous feature. Using a combination of computational, electrochemical, spectroscopic, and imaging probes, we find that holding the voltage between 0.6 and 1.0 VRHE results in a mildly-roughened Pt(111) surface [6], presumably due to an *OH-induced release of surface stress. The catalytic performance of this mildly roughened Pt(111) was tested for the oxygen reduction reaction (ORR) and carbon monoxide oxidation (CO Oxidation) where it was found that the ORR rate is seemingly structure insensitive and CO Oxidation rate is surprisingly structure sensitive [7]. Overall, this discovery demonstrates the importance of understanding how dynamic and steady operating conditions influence the electrode-electrolyte interface – critical for predicting, designing, and improving current commercial technologies and opening doors for the development of future technologies.

Bio

Arthur Shih’s research interests are in catalysis for the sustainable production of chemicals and energy, with emphasis on utilizing reaction kinetics and spectroscopy to understand catalytic mechanisms. He obtained his bachelor’s in Chemical Engineering from the University of Michigan during which he developed computer-based resources with H. Scott Fogler for his textbook “Elements of Chemical Reaction Engineering” and explored several research areas ranging from cancer detection to polymers to CO2 capture. He then earned his Ph.D., also in Chemical Engineering, from Purdue University with Fabio H. Ribeiro where he investigated the thermal-catalytic reduction of toxic nitrogen oxides in catalytic converters. Inspired by the growth and prowess of computational chemistry coupled with a desire to capitalize on cheap renewable electricity for the environment, he then moved to Leiden University and completed a postdoc in Chemistry with Marc Koper on the electrocatalysis of water splitting to H2 and O2 over well-defined single crystal electrodes. During that time he collaborated with several computational chemists around the world. He is currently a postdoctoral scholar in Materials Science and Engineering at Northwestern University with Sossina Haile working on nitride catalysts for high temperature electrochemical ammonia synthesis.

If unable to attend in person, please contact a.ramsey@northeastern.edu for the link.

Details

Date:
February 2, 2022
Time:
12:00 pm - 1:00 pm

Venue

024 East Village
360 Huntington Ave
Boston, MA 02115 United States

Organizer

Chemical Engineering
Phone:
617.373.2989
Website:
https://che.northeastern.edu/

Other

Department
Chemical Engineering
Topics
Seminar
Audience
Undergraduate, Graduate, Faculty