http://www.mdpi.com/journal/molecules/special_issues/heterogeneous-catalysis/ Dear Colleagues, Heterogeneous catalysis is key step in the synthesis pathway of a number of products in fields as diverse as petrochemicals, pharmaceuticals, fine chemicals but also in environmental applications;. The specific properties brought to the reaction by the supports open the route to enhanced efficiency, selectivity in synthesis, and improved competitiveness. This special issue of molecules dedicated to Heterogeneous Catalysis calls for both fundamental and applied contributions in this field of growing academic and industrial interests. Special attention will be paid to the characterization of materials (surface properties, diffusion characteristics), the identification of mechanisms and limiting steps, and the contribution of support properties to the orientation/selectivity of catalytic reactions. A special attention will be paid to original supports (based on renewable resources). Dr. Eric Guibal Guest Editor Submission All manuscripts should be submitted to molecules@mdpi.com with a copy to the Guest Editor. Manuscripts can be submitted until the deadline. Papers will be published continuously (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.   Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are refereed through a peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed Open Access monthly journal published by MDPI. Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this Open Access journal is 1400 CHF per accepted paper. http://www.mdpi.com/1420-3049/15/11/8400/ The greatest advantage of heterogeneous catalysis is the ease of separation, while the disadvantages are often limited activity and selectivity.  We report solvents that use tunable phase behavior to achieve homogeneous catalysis with ease of separation.  Tunable solvents are homogeneous mixtures of water or polyethylene glycol with organics such as acetonitrile, dioxane, and THF that can be used for homogeneously catalyzed reactions. Modest pressures of a soluble gas, generally CO2, achieve facile post-reaction heterogeneous separation of products from the catalyst. Examples shown here are rhodium-catalyzed hydroformylation of 1-octene and p-methylstyrene and palladium catalyzed C-O coupling to produce o-tolyl-3,5-xylyl ether and 3,5-di-tert-butylphenol. Both were successfully carried out in homogeneous tunable solvents followed by separation efficiencies of up to 99% with CO2 pressures of 3 MPa. Further examples in tunable solvents are enzyme catalyzed reactions such as kinetic resolution of rac-1-phenylethyl acetate and hydrolysis of 2-phenylethyl acetate (2PEA) to 2-phenylethanol (2PE). Another tunable solvent is nearcritical water (NCW), whose unique properties offer advantages for developing sustainable alternatives to traditional processes. Some examples discussed are Friedel-Crafts alkylation and acylation, hydrolysis of benzoate esters, and water-catalyzed deprotection of N-Boc-protected amine compounds. http://www.mdpi.com/1420-3049/15/11/8400/ Tue, 16 Nov 2010 00:00:00 CET Molecules 2010-11-16 15 11 Review 8400 8424 1420-3049 Combining the Benefits of Homogeneous and Heterogeneous Catalysis with Tunable Solvents and Nearcritical Water 2010-11-16 doi: 10.3390/molecules15118400 Ali Z. Fadhel Pamela Pollet Charles L. Liotta Charles A. Eckert http://www.mdpi.com/1420-3049/15/7/4815/ The catalytic effect of micelles, polymers (such as DNA, polypeptides) and nanoparticles, saturable receptors (cyclodextrins and calixarenes) and more complex systems (mixing some of the above mentioned catalysts) have been reviewed. In these microheterogeneous systems the observed changes in the rate constants have been rationalized using the Pseudophase Model. This model produces equations that can be derived from the Brönsted equation, which is the basis for a more general formulation of catalytic effects, including electrocatalysis. When, in the catalyzed reaction one of the reactants is in the excited state, the applicability (at least formally) of the Pseudophase Model occurs only in two limiting situations: the lifetime of the fluorophore and the distributions of the quencher and the probe are the main properties that define the different situations. http://www.mdpi.com/1420-3049/15/7/4815/ Fri, 09 Jul 2010 00:00:00 CEST Molecules 2010-07-09 15 7 Review 4815 4874 1420-3049 Microheterogeneous Catalysis 2010-07-09 doi: 10.3390/molecules15074815 Bernal Marchena Sánchez http://www.mdpi.com/1420-3049/15/6/3829/ Nanostructured single-site heterogeneous catalysts possess the advantages of classical solid catalysts, in terms of easy recovery and recycling, together with a defined tailored chemical and steric environment around the catalytically active metal site. The use of inorganic oxide supports with selected shape and porosity at a nanometric level may have a relevant impact on the regio- and stereochemistry of the catalytic reaction. Analogously, by choosing the optimal preparation techniques to obtain spatially isolated and well-characterised active sites, it is possible to achieve performances that are comparable to (or, in the most favourable cases, better than) those obtained with homogeneous systems. Such catalysts are therefore particularly suitable for the transformation of highly-functionalised fine chemicals and some relevant examples where high chemo-, regio- and stereoselectivity are crucial will be described. http://www.mdpi.com/1420-3049/15/6/3829/ Wed, 26 May 2010 00:00:00 CEST Molecules 2010-05-26 15 6 Review 3829 3856 1420-3049 Design and Use of Nanostructured Single-Site Heterogeneous Catalysts for the Selective Transformation of Fine Chemicals 2010-05-26 doi: 10.3390/molecules15063829 Dal Santo Liguori Pirovano Guidotti http://www.mdpi.com/1420-3049/15/5/3643/ The impact of immobilization of oxazaborolidines supported on silica via different substituents on the boron and nitrogen atoms is evaluated in the enantioselective reduction of acetophenone. The performances of the homogeneous analog oxazaborolidines and silica supported-ones are compared by varying different parameters. This article deals with the synthesis, characterization and catalytic evaluation of silica-supported oxazaborolidines, their recycling capabilities and regeneration limitations. http://www.mdpi.com/1420-3049/15/5/3643/ Tue, 18 May 2010 00:00:00 CEST Molecules 2010-05-18 15 5 Article 3643 3660 1420-3049 Enantioselectivity Induced by Oxazaborolidine Supported on Mesoporous Silica or by Its Analog in Homogeneous Phase 2010-05-18 doi: 10.3390/molecules15053643 Yune Quignard Molvinger http://www.mdpi.com/1420-3049/15/5/3428/ The enantioselective hydrogenation of 1-phenyl-1,2-propanedioneover Pt colloids stabilized with (R,S)-4,5-dihydro-4,5-diphenyl-2-(6-cyanopyridinyl)imidazoline (CI) supported on a meso-structured ZrO2 under a pressure of 40 bar of H2 at 298 K has been investigated. The metal loading in all catalysts was 1 wt%. The effect of the amount of chiral modifier on the metal particle size and on the catalytic behavior was analyzed. It was found that as the CI/Pt molar ratio increases from 2.5 to 3.5 the Pt crystal size decreases from 3.0 to 1.8 nm. All catalysts were very active in the studied reaction, with the most active one being the catalyst with smaller Pt particles, whereas the selectivity is higher in those catalysts with larger chiral modified Pt metal particles. http://www.mdpi.com/1420-3049/15/5/3428/ Wed, 12 May 2010 00:00:00 CEST Molecules 2010-05-12 15 5 Article 3428 3440 1420-3049 Chiral Pt/ZrO2 Catalysts. Enantioselective Hydrogenation of 1-phenyl-1,2-propanedione 2010-05-12 doi: 10.3390/molecules15053428 Urbina Campos Pecchi Claver Reyes http://www.mdpi.com/1420-3049/15/5/2994/ The work describes a study of the oxidation power of N-doped and undoped anatase TiO2, as well as TiO2 Degussa P25 suspensions for photocatalytic degradation of the herbicides RS-2-(4-chloro-o-tolyloxy)propionic acid (mecoprop) and 3,6-dichloro-pyridine-2-carboxylic acid (clopyralid) using visible and UV light. Undoped nanostructured TiO2 powder in the form of anatase was prepared by a sol-gel route. The synthesized TiO2, as well as TiO2 Degussa P25 powder, were modified with urea to introduce nitrogen into the structure. N-doped TiO2 appeared to be somewhat more efficient than the starting TiO2 (anatase) powder when visible light was used for mecoprop degradation. N-doped TiO2 Degussa P25 was also slightly more efficient than TiO2 Degussa P25. However, under the same experimental conditions, no degradation of clopyralid was observed in the presence of any of the mentioned catalysts. When the kinetics of mecoprop degradation was studied using UV light, more efficient were the undoped powders, while in the case of clopyralid, N-doped TiO2 Degussa P25 powder was most efficient, which is probably a consequence of the difference in the molecular structure of the two herbicides. http://www.mdpi.com/1420-3049/15/5/2994/ Tue, 27 Apr 2010 00:00:00 CEST Molecules 2010-04-27 15 5 Article 2994 3009 1420-3049 Photocatalytic Degradation of Mecoprop and Clopyralid in Aqueous Suspensions of Nanostructured N-doped TiO2 2010-04-27 doi: 10.3390/molecules15052994 Šojić Despotović Abramović Todorova Giannakopoulou Trapalis