5.1. Nanoalloys of Group 11 (Cu, Ag, Au) 865 5.1.1. Cu−Ag 866 5.1.2. Cu−Au 867 5.1.3. Ag−Au 870 5.1.4. Cu−Ag−Au 872 5.2. Nanoalloys of Group 10 (Ni, Pd, Pt) 872 5.2.1. Ni−Pd 872 * To whom correspondence should be addressed. Phone: +39010 3536214. Fax:+39010 311066. E-mail: ferrando@fisica.unige.it. † Universita di Genova. ‡ Argonne National Laboratory. § University of Birmingham. | As of October 1, 2007, Chemical Sciences and Engineering Division. Volume 108, Number 3

Nanoalloys: From Theory to Applications of Alloy Clusters and Nanoparticles

2.5. Stabilization of IL Emulsions by Nanoparticles 2623 3. Hydrogenations in ILs 2623 3.1. Hydrogenation on IL-Stabilized Nanoparticles 2623 3.1.1. Hydrogenation of 1,3-Butadiene 2623 3.1.2. Hydrogenation of Alkenes and Arenes 2624 3.1.3. Hydrogenation of Ketones 2624 3.2. Homogeneous Catalytic Hydrogenation in ILs 2624 3.3. Hydrogenation of Functionalized ILs 2625 3.3.1. Selective Hydrogenation of Polymers 2625 3.4. Asymmetric Hydrogenations 2626 3.4.1. Enantioselective Hydrogenation 2626 3.5. Role of the ILs Purity in Hydrogenation Reactions 2628

Catalysis in ionic liquids

This review analyses the literature from the early 1990s until the beginning of 2003 and covers the use of carbon nanotubes (CNT) and nanofibers as catalysts and catalysts supports. The article is composed of three sections, the first one explains why these materials can be suitable for these applications, the second describes the different preparation methods for supporting metallic catalysts on these supports, and the last one details the catalytic results obtained with nanotubes or nanofibers based catalysts. When possible, the results were compared to those obtained on classical carbonaceous supports and explanations are proposed to clarify the different behaviors observed.

Carbon nanotubes and nanofibers in catalysis

This review surveys recent advances in the applications of layered double hydroxides (LDHs) in heterogeneous catalysis. By virtue of the flexible tunability and uniform distribution of metal cations in the brucite-like layers and the facile exchangeability of intercalated anions, LDHs-both as directly prepared or after thermal treatment and/or reduction-have found many applications as stable and recyclable heterogeneous catalysts or catalyst supports for a variety of reactions with high industrial and academic importance. A major challenge in this rapidly growing field is to simultaneously improve the activity, selectivity and stability of these LDH-based materials by developing ways of tailoring the electronic structure of the catalysts and supports. Therefore, this Review article is mainly focused on the most recent developments in smart design strategies for LDH materials and the potential catalytic applications of the resulting materials.

Catalytic applications of layered double hydroxides: recent advances and perspectives

Automotive catalytic converters: current status and some perspectives

An overview about the effect of co-metal on the performance of Pd in bimetallic catalysts is presented. In the first part, the promotion of monometallic catalysts by addition of a second metal is described from a general point of view in terms of: (i) electronic effects; (ii) geometric effects; (iii) the occurrence of mixed sites; and (iv) the disappearance of the β-PdH phase. The second part presents the main methods to prepare bimetallic catalysts through the unselective and selective depositions of the co-metal precursor and the use of heterobinuclear complexes. The influence of preparation methods on the chemical state and the spatial distribution of both components are highlighted. In the last part, a short overview is given about the influence of co-metal addition on some important reactions in which Pd is the reference active phase: (i) selective hydrogenation of highly unsaturated aliphatic hydrocarbons; (ii) hydrogenation of aromatics or hydrodearomatisation; (iii) hydrogenation of nitrogen-containing compounds; (iv) reactions involving CO; and (v) hydrodechlorination.

Bimetallic palladium catalysts: influence of the co-metal on the catalyst performance

Conversion of chlorobenzene over palladium and rhodium catalysts of widely varying dispersion

Catalytic applications of Layered Double Hydroxides (LDH) or anionic clays have for a long time focused on the condensation reactions carried out with mixed oxides obtained by calcinations of Mg/Al LDH. However, the versatile character of materials prepared from these LDH exhibiting Lewis or Bronsted type basic sites has recently been underlined, and led us to contemplate extended applications in clean industrial processes. Moreover, due to their wide variety of compositions, LDH are also attractive precursors of multicomponent nanostructured catalysts. They give rise to supported metal catalysts whose metal support interaction and cooperation can be fine-tuned, as illustrated in pertinent case studies such as the hydrogenation of nitriles and the “one-pot” synthesis of methyl isobutyl ketone from acetone.

Catalysis by hydrotalcites and related materials

Conversion under hydrogen of dichlorodifluoromethane over supported palladium catalysts

The formation of nitroso-, azo- and azoxy-aromatics depends of a relatively complex scheme involving consecutive reactions. However, all different products can be produced in good yields with palladium catalysts, using optimised kinetics, selective poisoning or alloying. These reactions show different dependencies of the reaction rate on Pd particle size and alloying. Solvents have different roles, in addition to the usual one consisting in the solubilisation of the reactants: they can change the solubility of hydrogen, compete with the reactants for adsorption at the metal surface or catalyse side reactions.

Bernard Coq

Papers

Bimetallic palladium catalysts: influence of the co-metal on the catalyst performance

Conversion of chlorobenzene over palladium and rhodium catalysts of widely varying dispersion

Catalysis by hydrotalcites and related materials

Conversion under hydrogen of dichlorodifluoromethane over supported palladium catalysts

Hydrogenation and hydrogenolysis of nitro-, nitroso-, azo-, azoxy- and other nitrogen-containing compounds on palladium