Acquisition of a Scanning Tunneling Microscope to Enhance Research and Education in Stress-Controlled Catalysis.

摘要

We requested DURIP funding to acquire a scanning tunneling microscope (STM) and atomic force microscope (AFM) to enhance the research and educational objectives of the ARO-MURI program currently funded at Brown University on stress-controlled catalysis. We have acquired an Asylum MFP-3D-SA instrument to, which has been commissioned. We are currently working on developing the in situ electrochemical capability for the instrument to enable real-time surface measurements such as step density, defects and strains during electrocatalytic reactions. We have successfully used the instrument to (i) characterize the surface roughness evolution during electrochemical de-alloying of Pt-Cu thin films in order to isolate the strain effects on catalysis from those due to surface roughness changes. (ii) We have also characterized thin film catalysts during electrochemical cycling to determine the optimal conditions in which the films retain their integrity. We are currently working on developing an in situ electrochemical cell for the STM/AFM in order to monitor the catalyst surfaces while they are participating in electrochemical reactions. In addition to the MURI related activities, the instrument is made available to other researchers across Brown campus, with preference given to DoD sponsored research projects, thus ensuring broader research and educational impact of the STM/AFM.