October 11th, 2013
14:15/17:15 Aula N15 Edificio 2-Padiglione Nord 1°piano
(14:15/17:15 Room N15, Building 2-North pavillion, 1st floor)
Georges Guiochon, Professor and Distiguished Scientist of Analytical Chemistry
Department of Chemistry, University of Tennessee, USA
The Good, the Bad and the Ugly.
Preparative Chromatography, with gas, liquid or supercritical fluids?
Chromatography is a physico-chemical method used to purify compounds or to eliminate some
particular impurities. From its inception, it has suffered from its use of dilute solutions, thus
requiring the handling of large volumes of solvents under high pressures. This is a most costly
process. In practice, it is used essentially for the production of pharmaceuticals.
The nature of the mobile phase used in chromatography has a profound influence on the
performance of the process. An obvious critical requirement is that the feed be soluble in the
mobile phase. However, the density, the compressibility, and the viscosity of the mobile phase
play important roles on the performance of this process. The solubility requirement has
practically eliminated preparative gas chromatography from the realm of the practical industrial
separation processes. The very strange properties of the critical and supercritical fluids have
considerably delayed the development of practical applications of preparative supercritical fluid
chromatography. This method is now beginning to attract great interest from separation
engineers in pharmaceutical companies. Due to the low viscosity of supercritical fluids and the
high diffusion coefficients of compounds of moderate molecular weights in these fluids, this
method is growing in practical importance; it has found a significant niche, the preparative
production of pure enantiomers; it might even replace some day preparative liquid
chromatography in many current applications. So it is time to begin learning about its peculiar
properties, its possible advantages and its specific constraints.
November 25th, 2013
14:15/17:15 Aula N15 Edificio 2-Padiglione Nord 1°piano
(14:15/17:15 Room N15, Building 2-North pavillion, 1st floor)
Gregory Stephanopoulos
W.H. Dow Professor of Biotechnology & Chemical Engineering
Department of Chemical Engineering, MIT, USA
Metabolic Engineering
Metabolic Engineering is emerging as a new synthetic chemistry aiming at the construction of
microbial biocatalysts for the production of chemicals and fuels from renewable feedstocks such
as sugars, glycerol, volatile fatty acids, but also recently discovered abundant stores of natural
gas. This is accomplished through the engineering of proper pathways in microorganisms such
as bacteria and yeast, which convert the substrate to the designated target product. Principles of
catalysis and chemical reaction engineering are fundamental in guiding the process of
biocatalyst design, which is the essence of metabolic engineering.
November 29th, 2013
10:45 Aula MA1 Mancinelli
10:45 Room MA1 Mancinelli
Research at the Interface of Chemistry and Reaction Engineering for
Sustainable
Oxidation Technologies
Prof. Ive Hermans
Catalysis as an enabling technology for the sustainable synthesis of chemicals and the production of
energy has changed the world significantly. Improving the performance of existing technologies, and/or
enabling more sustainable reactions, which were hitherto unknown, or unfeasible on a large scale, can
both have a significant impact.
Within my research group, we unravel complex catalytic systems to their elementary reactions, in order
to identify the rate‐ and selectivity‐determining step(s). To do so, we use various experimental and
computational tools, ranging from chemical kinetics to (in situ) spectroscopy. Subsequently, we aim to
put the mechanistic pieces together in order to optimize the macroscopic performance, either through
improved reaction engineering or catalyst synthesis. During the lecture, this multidisciplinary approach
will be illustrated by case studies form both homogeneous and heterogeneous catalysis, focusing on
selective oxidations.
December 6th, 2013
14:15/17:15 Aula N15 Edificio 2-Padiglione Nord 1°piano
(14:15/17:15 Room N15, Building 2-North pavillion, 1st floor)
Maria Flytzani-Stephanopoulos
Robert and Marcy Haber Endowed Professor in Energy Sustainability
Department of Chemical and Biological Engineering, Tufts University, USA
Sustainable solutions to low-temperature hydrogen production: atomically dispersed
supported metal catalysts
A portfolio of energy solutions are envisioned for the foreseeable future, encompassing both renewable
and traditional fuels and processes to meet the ever growing demand for energy worldwide. From the
point of view of materials, particularly catalytic materials that can be used to optimize the relevant fuel
production and utilization processes, there is an urgent need for new active and stable catalysts that
comprise only minute quantities of precious metals, thus offering viable solutions to the way we generate
energy. Atomically dispersed supported metal catalysts offer new prospects for low-cost, sustainable
energy and chemicals production, as was discussed in a recent review [1].
Interest in atomically dispersed supported metal catalysts is demonstrated by the thriving research on the
preparation and stabilization of these sites through novel synthesis methods aimed at maximizing the
catalyst efficiency [1, 2]. In the area of fuel processing and hydrogen production, a new generation of
active and stable water-gas shift catalysts is needed for application to PEM fuel cells. Developmental
work along this line has been going on for more than fifteen years and has improved our understanding of
how best to design such catalysts. Parallel catalyst studies have been undertaken in recent years for the
steam reforming of methanol to produce hydrogen-on-demand in various small-scale applications. Here,
the catalyst must possess a high selectivity to hydrogen which requires high activity at low temperatures
and a reaction pathway that does not involve the water gas-shift reaction. Recent advances in the design
of such catalysts will be highlighted in a two-hour seminar series presentation.
a) We will draw from our experience with gold catalysts to demonstrate how atomically-designed gold
species catalyze the water-gas shift reaction.[3-5] We will point to similarities with copper as well as the
Pt-group metals. “Shape effects” of supports will be presented [4], while the promotion effect of alkali
addition will be shown as a general one, enabling unparalleled flexibility in the choice of supports,
including inert oxide[6] and carbon surfaces.[7] Generalized designs of low-temperature WGS catalysts
will be discussed.
b) For the low-temperature steam reforming of methanol, we will compare gold catalysts to platinum, and
discuss why the two are different, irrespective of the support or the promoter used. [8,9] The selectivity to
hydrogen depends on the metal chosen, even when the latter is present as atoms (cations) on the surface.
We will also demonstrate how to tailor the surface properties of oxide supports to maximize their
efficiency as carriers of the active metal species.
----------------------------------------------------------------------------------------------------------------------------- ---[1] M. Flytzani-Stephanopoulos, B.C. Gates, Annu. Rev. Chem. Biomol. Eng. 3 (2012)
[2] J.M. Thomas, Z. Saghi, P.L. Gai, Top. Catal. 54 (2011)
[3] Q. Fu, H. Saltsburg and M. Flytzani-Stephanopoulos, Science 301, 935-938 (2003)
[4] R. Si and M. Flytzani-Stephanopoulos, Angew. Chem. Int’l Ed. 47(15), 2884-2887 (2008)
[5] M. Yang, L. F. Allard, M. Flytzani-Stephanopoulos, J. Am. Chem. Soc. 135: 3768–3771 (2013)
[6] Y. Zhai, D. Pierre, R. Si, W. Deng, P. Ferrin, A. U. Nilekar, G. Peng, J. A. Herron, D. C. Bell, H. Saltsburg, M.
Mavrikakis, M. Flytzani-Stephanopoulos, Science 329, 1633-1636 (2010)
[7] B. Zugic, D.C. Bell, M. Flytzani-Stephanopoulos, Appl. Catal. B: Environmental, in press;
doi.org/10.1016/j.apcatb.2013.07.013
[8] N. Yi, R. Si, H. Saltsburg, M. Flytzani-Stephanopoulos, Appl. Catal. B: Env. 95(1-2), 87-92 (2010)
[9] M. B. Boucher, S. Goergen, N. Yi, M. Flytzani-Stephanopoulos, PCCP 13, 2517-2527 (2011)
December 13th, 2013
14:15/17:15 Aula N15 Edificio 2-Padiglione Nord 1°piano
(14:15/17:15 Room N15, Building 2-North pavillion, 1st floor)
Gregory Stephanopoulos
W.H. Dow Professor of Biotechnology & Chemical Engineering
Department of Chemical Engineering, MIT, USA
Biofuels
With increasing interest in bioenergy and biofuels, this lecture would address issues of feedstock
availability, impact on carbon footprint, available technologies for biofuels and economics.
Various platforms for biofuel production, such as the sugar, oil, algae and gas (synthesis or
otherwise) platforms could be discussed, along with the issues associated with engineering
microbes to achieve cost effective conversion of renewable substrates to various types of
biofuels.
February/March, 2014 …………..
Maria Flytzani-Stephanopoulos
Robert and Marcy Haber Endowed Professor in Energy Sustainability
Department of Chemical and Biological Engineering, Tufts University, USA
Title to be defined on the design of Single Atom Alloys for selective hydrogenation reactions or on the
desulfurization of fuel gases at high temperatures with regenerable sorbents (we can choose)