The article contains sections titled:



1.	Introduction	
1.1.	Types of Catalysis	
1.2.	Catalysis as a Scientific Discipline	
1.3.	Industrial Importance of Catalysis	
1.4.	History of Catalysis	
2.	Theoretical Aspects	
2.1.	Principles and Concepts	
2.1.1.	Sabatier's Principle	
2.1.2.	The Principle of Active Sites	
2.1.3.	Surface Coordination Chemistry	
2.1.4.	Modifiers and Promoters	
2.1.5.	Active Phase – Support Interactions	
2.1.6.	Spillover Phenomena	
2.1.7.	Phase-Cooperation and Site-Isolation Concepts	
2.1.8.	Shape-Selectivity Concept	
2.1.9.	Principles of the Catalytic Cycle	
2.2.	Kinetics of Heterogeneous Catalytic Reactions	
2.2.1.	Concepts of Reaction Kinetics (Microkinetics)	
2.2.2.	Application of Microkinetic Analysis	
2.2.3.	Langmuir – Hinshelwood – Hougen – Watson Kinetics	
2.2.4.	Activity and Selectivity	
2.3.	Molecular Modeling in Heterogeneous Catalysis	
2.3.1.	Density Functional Theory	
2.3.2.	Kinetic Monte Carlo Simulation	
2.3.3.	Mean-Field Approximation	
2.3.4.	Development of Multistep Surface Reaction Mechanisms	
3.	Development of Solid Catalysts	
4.	Classification of Solid Catalysts	
4.1.	Unsupported (Bulk) Catalysts	
4.1.1.	Metal Oxides	
4.1.1.1.	Simple Binary Oxides	
4.1.1.2.	Complex Multicomponent Oxides	
4.1.2.	Metals and Metal Alloys	
4.1.3.	Carbides and Nitrides	
4.1.4.	Carbons	
4.1.5.	Ion-Exchange Resins and Ionomers	
4.1.6.	Molecularly Imprinted Catalysts	
4.1.7.	Metal – Organic Frameworks	
4.1.8.	Metal Salts	
4.2.	Supported Catalysts	
4.2.1.	Supports	
4.2.2.	Supported Metal Oxide Catalysts	
4.2.3.	Surface-Modified Oxides	
4.2.4.	Supported Metal Catalysts	
4.2.5.	Supported Sulfide Catalysts	
4.2.6.	Hybrid Catalysts	
4.2.7.	Ship-in-a-Bottle Catalysts	
4.2.8.	Polymerization Catalysts	
4.3.	Coated Catalysts	
5.	Production of Heterogeneous Catalysts	
5.1.	Unsupported Catalysts	
5.2.	Supported Catalysts	
5.2.1.	Supports	
5.2.2.	Preparation of Supported Catalysts	
5.3.	Unit Operations in Catalyst Production	
6.	Characterization of Solid Catalysts	
6.1.	Physical Properties	
6.1.1.	Surface Area and Porosity	
6.1.2.	Particle Size and Dispersion	
6.1.3.	Structure and Morphology	
6.1.4.	Local Environment of Elements	
6.2.	Chemical Properties	
6.2.1.	Surface Chemical Composition	
6.2.2.	Valence States and Redox Properties	
6.2.3.	Acidity and Basicity	
6.3.	Mechanical Properties	
6.4.	Characterization of Solid Catalysts under Working Conditions	
6.4.1.	Temporal Analysis of Products (TAP Reactor)	
6.4.2.	Use of Isotopes	
6.4.3.	Use of Substituents, Selective Feeding, and Poisoning	
6.4.4.	Spatially Resolved Analysis of the Fluid Phase over a Catalyst	
6.4.5.	Spectroscopic Techniques	
7.	Design and Technical Operation of Solid Catalysts	
7.1.	Design Criteria for Solid Catalysts	
7.2.	Catalytic Reactors	
7.2.1.	Classification of Reactors	
7.2.2.	Laboratory Reactors	
7.2.3.	Industrial Reactors	
7.2.4.	Special Reactor Types and Processes	
7.2.5.	Simulation of Catalytic Reactors	
7.3.	Catalyst Deactivation and Regeneration	
7.3.1.	Different Types of Deactivation	
7.3.2.	Catalyst Regeneration	
7.3.3.	Catalyst Reworking and Disposal	
8.	Industrial Application and Mechanisms of Selected Technically Relevant Reactions	
8.1.	Synthesis Gas and Hydrogen	
8.2.	Ammonia Synthesis	
8.3.	Methanol and Fischer – Tropsch Synthesis	
8.3.1.	Methanol Synthesis	
8.3.2.	Fischer – Tropsch Synthesis	
8.4.	Hydrocarbon Transformations	
8.4.1.	Selective Hydrocarbon Oxidation Reactions	
8.4.1.1.	Epoxidation of Ethylene and Propene	
8.4.1.2.	Ammoxidation of Hydrocarbons	
8.4.2.	Hydroprocessing Reactions	
8.5.	Environmental Catalysis	
8.5.1.	Catalytic Reduction of Nitrogen Oxides from Stationary Sources	
8.5.2.	Automotive Exhaust Catalysis

Heterogeneous Catalysis and Solid Catalysts

Five new materials built from polyoxotungstates and Cu(II) ions as linkers have been synthesized by hydrothermal reactions from a mixture of sodium tungstate, copper chloride and bipyridine. The value of the initial pH, the nature of the heteroelement (P or Si) and of the ligand (2,2′- and/or 4,4′-bipyridine) permit the control of the nature of the polyoxotungstate clusters and their connectivity via the copper ions, and hence the dimensionality of the framework. A single phase has been obtained with silicon as heteroelement at an initial pH of 5, namely the 2D material [SiW12O40][Cu(2,2′-bpy)2]2·10H2O (1) with saturated Keggin polyoxotungstates linked by {Cu(2,2′-bpy)2}2+ groups. With phosphorous as heteroelement and at the same initial pH, three different structures have been isolated according to the nature of the ligand. Indeed, the two 1D materials [{Cu5(2,2′-bpy)5(H2O)(HPO4)(PO4)}PW11CuO39]·6H2O (2) with 2,2′-bpy and [4,4′-Hbpy][{Cu2(2,2′-bpy)2(4,4′-bpy)2.5}PW11CuO39]·16H2O (3) with a mixture of 2,2′- and 4,4′-bpy have been characterized, and a coordination polymer with polyoxometalate guests Na3[4,4′-Hbpy]{Cu4(4,4′-bpy)8(H2O)8}[PW11CuO39(H2O)][PW10Cu2O38(H2O)2]·38H2O (4) with 4,4′-bpy has been obtained. Finally, in basic medium (pH = 10) the unprecedented molecular cluster Na2[{Cu8(2,2′-bpy)8}(PW8O31)2]·15H2O (5) has been evidenced. Magnetic studies of compound 2 revealed that the predominant interactions involve only 4 paramagnetic centers, which are interacting within pairs, among the 6 Cu(II) centers. The χMT
				=
				f(T) curve can be fitted using the dinuclear expression appropriate to the HDVV isotropic exchange Hamiltonian H
				=
				−JS1×S2, with S1
				=
				S2
				=
				½ and J
				=
				−105.4 cm−1, showing strong antiferromagnetic interactions within the two Cu(II) pairs.

Molecular and multidimensional polyoxotungstates functionalized by {Cu(bpy)}2+ groups

Electrochemistry of Polyoxometalates: From Fundamental Aspects to Applications

While the reaction of [PW11O39]7- towards first row transition metal ions Mn+ under usual bench conditions only leads to monosubstituted {PW11O39M(H2O)} anions, we show that the use of this precursor under hydrothermal conditions allows to isolate a family of novel polynuclear molecular magnetic polyoxometalates (POMs). The hybrid asymmetric [FeII(bpy)3][PW11O39Fe2III(OH)(bpy)2]·12H2O complex (1) contains the dinuclear {Fe(μ-O(W))(μ-OH)Fe} core where one iron atom is coordinated to a monovacant POM while the other is coordinated to two bipyridine ligands. Magnetic measurements indicate that in 1 the FeIII centers are weakly antiferromagnetically coupled (J = -11.2 cm-1, Ĥ = -JŜ1Ŝ2) compared to {Fe(μ-O)(μ-OH)Fe} systems. This is due to the long distance between the iron center embedded in the POM and the oxygen atom of the POM bridging the two magnetic centers but also, as shown by DFT calculations, to the important mixing of bridging oxygen orbitals with orbitals of the POM tungsten atoms. (Hdmbpy)2[FeII(dmbpy)3]2[(PW11O39)2Fe4IIIO2(dmbpy)4]·14H2O (2) (dmby = 5,5’-dimethyl-2,2’-bpy) and H2[FeII(dmbpy)3]2[(PW11O39)2Fe4IIIO2(dmbpy)4]·10H2O (3) represent the first butterfly-like POM complexes. In these species, a tetranuclear FeIII complex is sandwiched between two lacunary polyoxotungstates which are pentacoordinated to two FeIII cations, the remaining paramagnetic centers being each coordinated to two dmbpy ligands. The best fit of the χMT = f(T) curve leads to Jwb = -59.6 cm-1 and Jbb = -10.2 cm-1 (Ĥ = -Jwb(Ŝ1Ŝ2 + Ŝ1Ŝ2* + Ŝ1*Ŝ2 + Ŝ1*Ŝ2*) – Jbb(Ŝ2Ŝ2*)). While the Jbb value is within the range of related exchange parameter previously reported for non-POM butterfly systems, the Jwb constant is significantly lower. As for complex 1, this can be justified considering Few-O distances. Finally, in absence of coordinating ligand, the dimeric complex [N(CH3)4]10[(PW11O39FeIII)2O]·12H2O (4) has been isolated. In this complex, the two single oxo-bridged FeIII centers are very

Fe2 and Fe4 Clusters Encapsulated in Vacant Polyoxotungstates: Hydrothermal Synthesis, Magnetic and Electrochemical Properties, and DFT Calculations

New compounds based on the association of polyoxometalates and cationic porphyrins or metalloporphyrins were prepared with the aim of obtaining new bi-functional catalysts. A combined study on the syntheses, characterization and catalytic activity of these compounds was performed. The new compounds have the general formula (porphyrin) x H y [XM 12 O 40 ]· z solv, x  = 0.75 or 1, X = P or Si and M = W or Mo. The porphyrins used were 5,10,15,20-tetrakis(4-pyridyl)porphyrin, 5,10,15,20-tetrakis(1-methyl-4-pyridinio)porphyrin, 5,10,15-tris(2,6-dichorophenyl)-20-(4-pyridyl)porphyrin, and 5,10,15-tris(2,6-dichlorophenyl)-20-(1-methyl-4-pyridinio)porphyrin, either as free bases or complexed with Mn III (one case with Zn II ). A few compounds with metal substituted Keggin anions ([PW 11 Y(H 2 O)O 39 ] n − , Y = Mn, Fe, Ni, Zn) were also prepared. All compounds were characterized by spectroscopic and analytical techniques. The oxidation of cis -cyclooctene, geraniol and (+)-3-carene by hydrogen peroxide catalysed by the polyoxometalate/Mn III porphyrin associations and co-catalysed by ammonium acetate was examined. Some of the associations significantly increased the percentage of conversion of the substrates relatively to the respective metalloporphyrin alone. However, the regio-, chemo- and stereoselectivity of the oxidation reactions catalysed by metalloporphyrins were globally preserved: c is -cyclooctene was selectively epoxidised to epoxycyclooctane; geraniol gave 6,7-epoxygeraniol as the major product and (+)-3-carene was preferably oxidised to the α-3,4-epoxycarane. In the conditions studied, the polyoxoanions seem to contribute mainly to stabilise the metalloporphyrin against deactivation during catalytic cycles.

Association of Keggin-type anions with cationic meso-substituted porphyrins : synthesis, characterization and oxidative catalytic studies

Investigation of the thermal decomposition of some metal-substituted Keggin tungstophosphates

Study of polyoxotungstates with the Keggin structure by cyclic voltammetry

The thermal decomposition of the tetrabutylammonium (TBA) salts (TBA)4H3[PW11O39] and (TBA)4Hx[PW11M(H2O)O39]·nH2O, x = 3-(oxidation number of M), M = Mn(II), Co(II), Ni(II), Cu(II) or Fe(III), n = 0–3, has been studied by thermal analyses and the decomposition products identified by powder X-ray diffraction, FTIR and NMR spectroscopy. The organic cation started to decompose in the 150–200°C range. The release of the metal M from the substituted polyoxoanions accompanied the initial degradation of the organic cations and [PW12O40]3− was formed as an intermediate at ca. 300°C. For a comparison, the thermal decomposition of (TBA)3[PW12O40] was also investigated. The thermal decomposition of the potassium salts of the lacunary and metal-substituted anions was also studied, but the formation of [PW12O40]3− was not observed. The temperature of decomposition of the [PW11M(H2O)O39](4+x)− anions was at least 150°C higher for the potassium than for the tetrabutylammonium salts. This study exemplified that the thermal stability of some Keggin anions was dependent on the counter-cation present.

Fatima A. S. Couto

Papers

Investigation of the thermal decomposition of some metal-substituted Keggin tungstophosphates

Study of polyoxotungstates with the Keggin structure by cyclic voltammetry

Investigation of the Thermal Decomposition of Some Metal-Substituted Keggin Tungstophosphates.