Carnegie Mellon University
Catalysis and Surface Science Lab

Catalysis and Surface Science Lab

ChemE houses one of the best equipped academic catalysis and surface analysis laboratories in the US.  The CCS lab is used by the faculty, students and postdocs of the CSS group for a variety of fundamental studies of surface chemistry relevant to problems in catalysis, enantioselective surface chemistry, adsorption, tribology, and corrosion.  

Much of the equipment has been designed and assembled in house and some is truly unique, giving the lab capabilities that are unmatched elsewhere.  In recent years, the CSS group has invested heavily in the development of instrumentation and tools for high throughput catalysis and surface science.  These capabilities include the preparation and characterization of alloy libraries in the form of thin Composition Spread Alloy Films (CSAFs) that span composition space; AxByC1-x-y, x = 0 → 1 and y = 0 → 1-x in a  space of 1 cm2.  The CSS Lab houses two UHV chambers with rotating shadow mask deposition tools for preparation of CSAFs.  Each can deposit up to four alloy components simultaneously with composition gradients in any desired direction across the substrate.  Another form of high throughput library that can be prepared in the CSS Lab is the Surface Structure Spread Single Crystal (S4C), a single crystal polished with a curved surface that exposes crystallographic planes with a continuous distribution of orientations that span the stereographic projection, M(hkl).

In addition, the CSS Lab has six versatile ultrahigh vacuum, surface preparation and analysis chambers equipped with state of-the-art instrumentation including:

* five x-ray photoemission spectrometers (XPS)
* two ultra-violet photoemission spectrometers (UPS)
* five low energy electron diffraction (LEED) optics
* high resolution electron energy loss spectrometer (HREELS),
* ~12 mass spectrometers
* two Fourier transform infrared (FTIR) spectrometers
* two low energy ion scattering spectrometers (LEIS)
* a Raman microscope
* a secondary electron microscope (SEM)
* energy dispersive x-ray detector (EDX)
* electron backscatter diffraction (EBSD)

The SEM with combined EDX and EBSD is used to map the bulk characteristics (composition and phase) of alloys across composition space spanned by the CSAFs. One of UHV chambers is capable of spatially resolved XPS, UPS and LEIS to allow high throughput mapping of surface characteristics across CSAF and S4C libraries.  The UHV chambers all have equipment for surface preparation including exposure to gases, organic vapors and Knudsen cells for exposure to high molecular weight organics such as amino acids.  

The CSS Lab is also well equipped with catalytic reactor systems.  Two commercial systems are used for study of steady state catalytic reaction kinetics and for exposure of various samples and CSAFs to catalytic reaction conditions. In addition, the CSS Lab has two unique multichannel microreactor array systems for spatially resolved study of catalytic reaction kinetics across CSAFs.  These high throughput reactors allow concurrent measurement of catalytic reaction kinetics at 100 different alloy compositions.  The combination of high throughput surface analysis and high throughput mapping of catalytic reaction kinetics across CSAFs allows study of alloy catalysis with unprecedented resolution across composition space.