It is possible to say that zeolites are the most widely used catalysts in industry They are crystalline microporous materials which have become extremely successful as catalysts for oil refining, petrochemistry, and organic synthesis in the production of fine and speciality chemicals, particularly when dealing with molecules having kinetic diameters below 10 A The reason for their success in catalysis is related to the following specific features of these materials:1 (1) They have very high surface area and adsorption capacity (2) The adsorption properties of the zeolites can be controlled, and they can be varied from hydrophobic to hydrophilic type materials (3) Active sites, such as acid sites for instance, can be generated in the framework and their strength and concentration can be tailored for a particular application (4) The sizes of their channels and cavities are in the range typical for many molecules of interest (5-12 A), and the strong electric fields2 existing in those micropores together with an electronic confinement of the guest molecules3 are responsible for a preactivation of the reactants (5) Their intricate channel structure allows the zeolites to present different types of shape selectivity, ie, product, reactant, and transition state, which can be used to direct a given catalytic reaction toward the desired product avoiding undesired side reactions (6) All of these properties of zeolites, which are of paramount importance in catalysis and make them attractive choices for the types of processes listed above, are ultimately dependent on the thermal and hydrothermal stability of these materials In the case of zeolites, they can be activated to produce very stable materials not just resistant to heat and steam but also to chemical attacks Avelino Corma Canos was born in Moncofar, Spain, in 1951 He studied chemistry at the Universidad de Valencia (1967−1973) and received his PhD at the Universidad Complutense de Madrid in 1976 He became director of the Instituto de Tecnologia Quimica (UPV-CSIC) at the Universidad Politecnica de Valencia in 1990 His current research field is zeolites as catalysts, covering aspects of synthesis, characterization and reactivity in acid−base and redox catalysis A Corma has written about 250 articles on these subjects in international journals, three books, and a number of reviews and book chapters He is a member of the Editorial Board of Zeolites, Catalysis Review Science and Engineering, Catalysis Letters, Applied Catalysis, Journal of Molecular Catalysis, Research Trends, CaTTech, and Journal of the Chemical Society, Chemical Communications A Corma is coauthor of 20 patents, five of them being for commercial applications He has been awarded with the Dupont Award on new materials (1995), and the Spanish National Award “Leonardo Torres Quevedo” on Technology Research (1996) 2373 Chem Rev 1997, 97, 2373−2419

From Microporous to Mesoporous Molecular-Sieve Materials and Their Use in Catalysis

Hydrogen Spillover. Facts and Fiction

Sulfated zirconia and its modified versions as promising catalysts for industrial processes

This review article deals with recent progress in the preparation of sulfated zirconia (SZ)-bassed, strong solid-acid catalysts, the characterization of their physicochemical properties and the evaluation of their catalytic performance in various promising applications. Strong emphasis was put on discussion of controversial issues such as the strength of acid sites, the nature of active sites, the reaction mechanism, and the role and state of supported platinum. An important part of this work was devoted to recent catalytic applications.

Sulfated Zirconia-Based Strong Solid-Acid Catalysts: Recent Progress

Acid catalysts in industrial hydrocarbon chemistry.

Characterization of WOx/ZrO2by Vibrational Spectroscopy andn-Pentane Isomerization Catalysis

Low-Temperature Superacid Catalysis: Reactions of n-Butane Catalyzed by Iron- and Manganese-Promoted Sulfated Zirconia

Activation of ethane in the presence of solid acids: Sulfated zirconia, iron- and manganese-promoted sulfated zirconia, and zeolites

First-row transition metals were tested in a flow reactor as promoters of sulfated zirconia for the isomerization ofn-butane at 373 K and 0.005 barn-butane partial pressure. The activity of each of the sulfated zirconia samples increased through a maximum and then decreased with time on stream. In order of increasing activity measured at the maximum, the effect of the promoters increased from right to left in the periodic table: zinc, nickel, cobalt, iron, and manganese. Iron and manganese increased the activity by. 2–3 orders of magnitude. The causes of the promoter action are not elucidated; the promoters may play noncatalytic roles as initiators.

Tsz-Keung Cheung

Papers

Characterization of WOx/ZrO2by Vibrational Spectroscopy andn-Pentane Isomerization Catalysis

Low-Temperature Superacid Catalysis: Reactions of n-Butane Catalyzed by Iron- and Manganese-Promoted Sulfated Zirconia

Activation of ethane in the presence of solid acids: Sulfated zirconia, iron- and manganese-promoted sulfated zirconia, and zeolites

Manganese, iron, cobalt, nickel, and zinc as promoters of sulfated zirconia for n -butane isomerization

Spectroscopic and Microscopic Characterization of Iron- and/or Manganese-Promoted Sulfated Zirconia