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Amsterdam, Netherlands

Gluhoi A.C.,Avantium Technologies | Bakker J.W.,Leiden University | Nieuwenhuys B.E.,Leiden University | Nieuwenhuys B.E.,TU Eindhoven
Catalysis Today | Year: 2010

The hydrogenation of C2H2 in the presence and the absence of C2H4 has been studied over un-promoted and promoted Au/Al2O3. A number of parameters have been varied: the Au particle size, the pre-treatment conditions (hydrogen versus oxygen) and the nature of the promoters. Promoters include ceria, lithium and barium oxides. Our results show that hydrogenation of C2H2 proceeds with 100% selectivity towards C2H4, both in the presence and the absence of C2H4. Moreover, there is a strong dependence of the catalytic performance on the size of the Au particles: Au particles below 3 nm enhance the C2H2 conversion both in the absence and the presence of C2H4, without decreasing the selectivity to C2H4. Furthermore, metallic Au and Ce4+ appear to be more effective than Au3+ and Ce3+. Our findings also indicate that Li2O has a beneficial effect on C2H2 conversion, while BaO has a slight detrimental effect, both having no influence on the selectivity to C 2H4. The key to 100% selectivity to C2H 4 resides in non-competitive adsorption of C2H2 and C2H4 on the Au surface when both hydrocarbons are present in the feed. The deactivation during C2H2 hydrogenation is a reversible process and is due to accumulation of C deposits on the catalyst surface, as result of C2H2 adsorption on different active Au sites. These deposits can be easily burned off by a thermal treatment in oxygen. © 2010 Elsevier B.V. All rights reserved. Source

Urbanus J.,TNO | Roelands C.P.M.,TNO | Mazurek J.,Avantium Technologies | Verdoes D.,TNO | Ter Horst J.H.,Technical University of Delft
CrystEngComm | Year: 2011

We demonstrate the potential of co-crystallization combined with electrochemistry for in situ product removal of carboxylic acids. Proof-of-principle is established using a cinnamic acid:3-nitrobenzamide (HCA:NBA) co-crystal system. This technology can be applied in the bio-based production of essential "green" building blocks. © 2011 The Royal Society of Chemistry. Source

Habgood M.,University College London | Deij M.A.,Avantium Technologies | Mazurek J.,Avantium Technologies | Price S.L.,University College London | Ter Horst J.H.,Technical University of Delft
Crystal Growth and Design | Year: 2010

Isonicotinamide (INA) co-crystallizes with carbamazepine (CBZ), as do nicotinamide (NA) and benzamide. The structure of CBZ-INA form II is solved from powder and is shown to be isostructural with CBZ-NA. However picolinamide (PA), despite its similarity to the other pyridine carboxamides in the homologous series, does not appear to form a co-crystal with CBZ. We compare and contrast the use of computed crystal energy landscapes and binary and ternary phase diagrams to explain this behavior. Two 1:1 co-crystal structures of CBZ and INA were predicted to have lower or comparable lattice energies than the sum of the pure component lattice energies. These structures corresponded to the known co-crystal structures. On the other hand, lattice energies of predicted CBZ-PA co-crystal structures were less stable than the pure component lattice energies, implying that CBZ and PA would not form a co-crystal. This is consistent with the experimental evidence. Examination of the hypothetical crystal structures for CBZ-INA and for CBZ-PA explains this in terms of intermolecular hydrogen-bonding capability. Thus computed crystal energy landscapes are more reliable than simple crystal engineering concepts in understanding co-crystal formation, and can provide a useful complement to experimental co-crystal screening. © 2009 American Chemical Society. Source

Ras E.-J.,Avantium Technologies | Ras E.-J.,University of Amsterdam | Louwerse M.J.,University of Amsterdam | Rothenberg G.,University of Amsterdam
Catalysis Science and Technology | Year: 2012

We report new experimental results on the hydrogenation of 5-ethoxymethylfurfural, an important intermediate in the conversion of sugars to industrial chemicals, using eight different M/Al 2O 3 catalysts (M = Au, Cu, Ni, Ir, Pd, Pt, Rh, and Ru) under various conditions. These data are then compared with the results for 48 bimetallic supported catalysts. The results are explained using a simple and effective model, applying catalyst descriptors based on Slater type orbitals (STOs). Each metal is described using four parameters: the height of the orbital peak, the distance of the peak from the metal atom centre, the peak width at half height, and the peak skewness. Importantly, all these parameters are derived from one simple equation, so the calculation is fast and robust. We then apply these descriptors for modeling the hydrogenation data using multivariate methods. Despite the inherent complexity of the reaction network, these simple models describe the catalysts' performance well. The general application of such descriptor models to in silico design and performance prediction of solid catalysts is discussed. © 2012 The Royal Society of Chemistry. Source

Gosselink R.J.A.,Agrotechnology and Food Innovations B.V. | Van Dam J.E.G.,Agrotechnology and Food Innovations B.V. | De Jong E.,Avantium Technologies | Scott E.L.,Wageningen University | And 3 more authors.
Holzforschung | Year: 2010

Functional properties of technical lignins need to be characterized in more detail to become a higher added value renewable raw material for the chemical industry. The suitability of a lignin from different plants or trees obtained by different technical processes can only be predicted for selected applications, such as binders, if reliable analytical data are available. In the present paper, structure dependent properties of four industrial lignins were analyzed before and after successive organic solvent extractions. The lignins have been fractionated according to their molar mass by these solvents extractions. Kraft and soda lignins were shown to have different molar mass distributions and chemical compositions. Lignin carbohydrate complexes are most recalcitrant for extraction with organic solvents. These poorly soluble complexes can consist of up to 34% of carbohydrates in soda lignins. Modeling by principle component analysis (PCA) was performed aiming at prediction of the application potential of different lignins for binder production. The lignins and their fractions could be classified in different clusters based on their properties, which are structure dependent. Kraft softwood lignins show the highest potential for plywood binder application followed by hardwood soda lignin and the fractions of Sarkanda grass soda lignin with medium molar mass. Expectedly, the softwood lignins contain the highest number of reactive sites in ortho positions to the phenolic OH group. Moreover, these lignins have a low level of impurities and medium molar mass. © 2010 by Walter de Gruyter Berlin New York. Source

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