Funding from DOE was utilized strategically to build instrumentation for in situ interrogation of reactions and surfaces under catalytic conditions. We have invested in: (i) a Hummingbird gas-cell holder to image morphological changes on nanoporous catalyst surfaces, at atmospheric pressures, using the scanning and transmission electron microscopes (STEMs & TEMs) at Harvard. (ii) a custom-build X-ray absorption system that will be used to probe materials composition and intermediates on the surface under reaction conditions. (iii) An Agilent HPLC coupled to ATRIR and the combined instrumentation, available at Tufts, as a means of probing liquid reactions. In addition we are in the process of purchasing Ion-scattering set-up/XPS upgrade as a new capability. The IMASC equipment have started creating value to the overall center based on usage by a large number of PIs involved and wider availability.
An array of materials characterization facilities are housed in the Center for Nanoscale Systems (CNS; http://www.cns.fas.harvard.edu). CNS provides facilities for SEM, TEM, Raman spectroscopy and XPS. Specific facilities that are currently used are: (a) the LEO 982 scanning electron microscope (SEM), having high-resolution imaging (1 nm at 20 keV, 4 nm at 1 keV) at beam energies of between 200 and 20,000 eV; (b) a JEOL 2100 transmission electron microscope with a stage that can heat up to ~ 1200K; (c) a multi-user
Temporal Analysis of Products (TAP) reactor used for kinetic studies of catalysis
X-ray photoelectron spectrometer (ESCA SSX-100); (d) a custom-built multiline Raman spectrometer and (e) in situ Hummingbird gas-cell holder that allows imaging of samples at atmospheric pressures and can observe morphological changes in nanoporous gold materials in various gaseous environments, such as oxygen, air, hydrogen, and ozone.
Additional characterization facilities available within the Friend group are: XPS/UPS system, a variable temperature, ultrahigh vacuum atomic force microscope (AFM; Omicron), an ultrahigh vacuum system equipped with a Hiden mass spectrometer for photo-desorption and temperature programmed experiments to measure surface reactivity, and a flow reactor equipped with a broad-band light source for photolysis and a GC-mass spectrometer system for analysis of product distributions. A TAP II (Temporal Analysis of Products) reactor is being used for carrying out catalytic studies of the nanoporous, meso-scale materials, allowing transient studies under Knudsen flow conditions or steady-state operation at atmospheric pressure.
Odyssey, Harvard’s largest supercomputer, offers users over 2.5 Petabytes of raw storage, more than 17,000 processing cores, and numerous software modules and applications. Research Computing can also host and create scientific applications not already on the Odyssey system. The Kaxiras group also has access to the XSEDE National Network of Supercomputers (an NSF funded facility).
Computational Facilities & Capabilities
Harvard’s Supercomputer. IMASC computational researchers are taking advantage of Odyssey, Harvard’s largest supercomputer, that offers users over 2.5 Petabytes of raw storage, more than 60,000 processing cores, and numerous software modules and applications. Research Computing can also host and create scientific applications not already on the Odyssey system.
XSEDE National Network of Supercomputers. The Kaxiras group also has access to the XSEDE National Network of Supercomputers (an NSF funded facility) and NERSC supercomputers (https://www.nersc.gov/).
DOE – ASCR Facilities.IMASC is also taking advantage of the Advanced Scientific Computing Research (ASCR) facilities.Two IMASC’s computational proposals, one each at ALCF and OLCF, have received computational time.
Lawrence Berkeley National Laboratory
The following state-of-the-art Surface Science facilities equipped with various Microscopes, both home built, and commercial are available: Variable temperature (100 K-350 K) Scanning Tunneling Microscope (VT-STM), equipped with Low Energy Electron Diffraction (LEED), Ion Sputtering (IS), Mass Spectrometer (MS) and Auger Electron Spectroscopy (AES) in an ultra-high vacuum (UHV) chamber; A variable temperature (100 K- 350 K) Atomic Force Microscope (VT-AFM) in a UHV chamber with LEED, AES, IS and MS; A liquid He (4 K) cooled STM, with preparation chamber equipped with LEED, AES, IS and MS; A liquid He (4 K) cooled non-contact AFM, with preparation chamber equipped with LEED, AES, IS and MS; A Molecular Imaging AFM operating in air and in controlled gas environments; reaction cells for X-ray Absorption Spectroscopy (XAS), with gas circulation and laser assisted sample heating. Used in catalysis experiments at the Advanced Light Source (ALS); access to ALS allows in situ Ambient Pressure X-ray Photoelectron Spectroscopy (APXPS)
Lawrence Livermore National Lab
LLNL Additive Micromanufacturing Laboratory with capabilities including a Projection Microstereolithography system (two new systems are in assembly), four Electrophoretic Deposition systems, and three Direct Ink Writing systems. This laboratory also houses a Stratasys Dimension 1200 SST 3D printer capable of printing 3D structures from ABS thermoplastic in a working volume of 10 Å~ 10 Å~ 12 inches, a 3D Systems Cube desktop fused deposition modeling 3D printer, and an Ultimaker desktop 3D printer capable of fabricating structures with multiple Polymers.
The labs here are equipped with several reactor systems, including two recycle reactors for low-surface area sample tests and five tubular flow reactor systems; catalyst preparation apparatus; atomiclayer deposition apparatus; gas and solid analysis systems, including three gas
Reactor set-up for TPSR/MS studies
chromatographs,four mass spectrometers, two TGA assemblies, flow controllers, FTIR and NDIR gas analyzers, a UV-VIS spectrophotometer, data acquisition systems, as well as numerous computers.What is shown in the figure is a AutoChem II 2920 reactor system (Micromeritics) coupled with a mass spectrometer; Temperature-programmed-reduction (TPR), and temperature-programmed surface reaction (TPSR) coupled with mass spectrometry; Parr reactors and other high-pressure reactor systems.