Site: Max-Planck-Institut für Kohlenforschung
D45470 Mülheim an der Ruhr, Germany
Tel: (49) 208-306 1; Fax: (49) 208-306 2980
Date Visited: 16 October 1997
WTEC: D. Cox (report author)
The Max-Planck-Institut für Kohlenforschung (the Max Planck Institute of Coal Research) in Mülheim was founded in 1912 as one of the first institutes of the former Kaiser-Wilhelm-Gesellschaft as an independent foundation. It is one of more than 70 Max Planck institutes in Germany but has kept its independent legal status under private law and is a recognized nonprofit organization. It is well known for its discoveries of the Fischer-Tropsch process and the Ziegler catalysts. The patents from these discoveries as well as others have generated significant additional income for the institute over the years (particularly notable are the patents of Karl Ziegler, whose first patent for the low-pressure polyethylene synthesis was granted in 1953) and have allowed it to generously fund research efforts of the staff. The expiration of the Ziegler patents has reduced the outside income, and as a result, the funding levels are beginning to come more into line with those of other Max-Planck institutes.
This institute has a history of exploiting the inventions made in the institute by retaining ownership of all patents through a trusteeship (the Studiengesellschaft Kohle mbH) which grants licenses producing this additional income. Presently the institute has about 30 nonexpired patents and published patent applications. The Studiengesellschaft Kohle also grants licenses for the usage of software developed within the Max-Planck-Institut für Kohlenforschung; for example, the mass spectrometry software MassLib® was developed at this institute.
As of the time of the WTEC visit, the staff has about 220 permanent employees, about 50 of which are staff scientists. In addition, there are about 100 graduate students, postdocs, and guest scientists distributed among about 24 research groups focusing in the following areas:
The institute has a rich history in the area of chemical catalysis, built in large part on Ziegler's Nobel Prize-winning work in ethylene polymerization. The present research areas at the institute focus on synthesis of novel materials for applications in catalysis, energy storage, and separations. The efforts that are particularly applicable to nanoscale science and technology are those involved in studying highly selective catalysts and in generating microporous inorganic oxide materials and high surface area materials for chemical energy storage. Research in these areas is centered in several of the groups at Mülheim, particularly those of Prof. Dr. M.T. Reetz, Dr. J.S. Bradley, Prof. Dr. W.F. Maier, and Prof. Dr. H. Bogdanovic.
The institute is very well equipped as are the individual research groups with world class capabilities in NMR spectroscopy, X-ray characterization and Modeling, Optical Spectroscopy, Mass Spectrometry, Electron Microscopies, and Chromatography as examples.
Prof. Bönnemann has developed widely applicable synthetic methods for the preparation of surfactant-stabilized colloidal metal nanoclusters (1-10 nm, mono- and plurismetallic) based on reduction of metal salts with surfactant-containing reducing agents and the use of surfactant cation salts of metal complex anions. These materials, which have high metal nanocluster content and high solubility (up to 1 mole of metal/litre) in organic solvents or water, have been applied as catalyst precursors both in liquid dispersion and in supported form for a variety of organic reactions, e.g., selective (including enantioselective) hydrogenation and oxidation. Further fields of application are bimetallic fuel cell catalysts, magnetic fluids, nanometal pigments for magneto-optical data storage, and magnetic cell separation in biological samples.
Prof. Reetz, in addition to his research effort, is one of two scientific directors at the MPI für Kohlenforschung. He uses electrochemical reduction of metal salts to prepare highly dispersed colloidal transition metal nanoclusters and supported nanoclusters, a process for which a patent has been granted. Variation of the current density and the temperature as well as the polarity of the solvent during the electrochemical synthesis allows control of the size of the nanoclusters. The stabilizing surfactant shell surrounding these nanoclusters can be visualized with a combination of STM and high resolution TEM. The clusters are evaluated as catalysts for selective organic transformations including carbon-carbon bond forming reactions. (Science 267:367, 1995).
Dr. Bradley has long been involved in metal cluster and metal colloid chemistry areas of nanoscale science and technology. He joined the MPI für Kohlenforschung in 1995. His present emphasis in nanoscale materials focuses on the development of new synthetic methods for colloidal transition metal nanoclusters, their spectroscopic characterization (infrared, NMR, and extended X-ray absorption fine structure [EXAFS] spectroscopy), and the use of in-situ kinetic catalytic probes to define their surface chemistry. In addition, research is ongoing on the preparation from organometallic precursors of microporous nonoxide ceramics and their use in base-catalyzed reactions. For example, high surface area (400m2/g) silicon amidonitride with a mean pore diameter of 7 Å has been prepared.
Prof. Maier's main research area is aimed towards design of new heterogeneous catalysts that will have isolated active centers in a microporous metal oxide matrix (amorphous microporous mixed oxides, AMM). Guidance for this approach is taken from the fact that enzymes and zeolites are the most selective catalysts, having in common an isolated active center and a shape-selective environment around the active site. Prof. Maier's group has developed techniques to prepare AMM materials by a special sol-gel process that allows control of the chemical composition, pore size (0.5-1.0 nm), porosity, and surface polarity in a single preparation step. AMM catalysts have a narrow micropore distribution comparable to those of zeolites, and a homogeneous elemental distribution. They have produced shape-selective catalysts based on microporous titania, zirconia, and alumina. The AMM materials have been shown to be selective catalysts for oxidation, hydrogenation, alkylation, and hydrocracking.
AMM membranes, prepared by dip-coating of asymmetric support membranes, are then used as catalytic membrane reactors. The catalytic membrane reactor allows the combination of catalytic activity with the permselectivity of the membranes to improve the selectivity of heterogeneously catalyzed reactions. Novel applications of AMM membranes include poison-resistant catalysis and complete suppression of secondary reactions with membrane catalysts.
The nanomaterial research in Prof. Bogdanovic's group focuses on the preparation of highly reactive, highly dispersed inorganic materials (metal and intermetallic cluster materials, metal hydrides, metal carbides) from molecular organometallic precursors. Materials based on active magnesium hydride were discovered for use as reversible hydrogen storage systems. Highly dispersed metals, intermetallics, and carbides have been evaluated in a variety of catalytic organic reactions.