“Shape Selective Catalysis: Chemicals Synthesis and Hydrocarbon

“Shape Selective Catalysis: Chemicals Synthesis and. Hydrocarbon Processing”. C. Song, J. M. Garcés and Y. Sugi, Eds., ACS Symp. Ser. 738, Amer. ...
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Energy & Fuels, Vol. 16, No. 1, 2002 219 “Shape Selective Catalysis: Chemicals Synthesis and Hydrocarbon Processing”. C. Song, J. M. Garce´s and Y. Sugi, Eds., ACS Symp. Ser. 738, Amer. Chem. Soc., Washington, DC, 2000, 410 pp. This book is a collection of 27 review and current research reports on shape-selective reactions with zeolite and other microporous catalysts presented at the spring 1998 American Chemical Society meeting, Division of Petroleum Chemistry. Zeolites are an important class of heterogeneous catalysts utilized in number of industrial petrochemical processes, and shape selectivity is a key parameter to controlling the reaction selectivity. The book is divided into six sections and includes general reviews, catalysis of organic reactions, methanol conversion to gasoline and olefins, paraffin cyclization and aromatization, conversion of monocyclic hydrocarbons, and new concepts and catalytic materials. The first section includes an introduction paper by the editors, C. Song, J. M. Grace´s, and Y. Sugi, and two review papers by P. B. Weisz and N. Y. Chen. The reviews by the latter two, who are pioneers in the field of shape-selective catalysis, cover the history, science, and new technology that resulted from the research, primarily at Mobil, and are highly authoritative and comprehensive. This section delineates the important concepts giving many examples, including several reactions that were ultimately commercialized. These first three papers are the highlight of the book. The section on catalysis of organic reactions begins with a short review by P. B. Venuto, which summarizes the industrial applications utilizing shape selectivity by medium pore zeolites. While the number of new applications is impressive, it would have been nice if this review had been longer and included some of the key reactions and intermediates that lead to these new technologies. The remaining papers in this section include a recent research report on oxidation by TS-1. Shape selectivity is thought to account for the selectivity of bulky oxidation products. The final paper presents recent results for oxidation by an interesting new class of microporous Mn octahedral molecular sieves. These and similar new microporous materials synthesized in the past few years have not yet led to any new commercial processes; however, their discovery and study are relatively new compared to conventional zeolites and aluminophosphate molecular sieves. The section on conversion of methanol to olefins and gasoline contains an excellent review by C. D. Chang. This review is shorter and similar to others by the author, but it is still a quality paper. The second paper summarizes the use of the current best catalysts, silicoaluminomphospates, for the production of olefins. Modification of the acidic strength, pore structure, and site density yield catalysts highly selective for ethylene.

Two papers are included in the section on paraffin cyclization and aromatization. The first demonstrates how small changes in the pore structure due to coke or amorphous material has a strong influence on shape selectivity and the aromatic selectivity of the catalyst during cracking of heptane. In the second paper, the conversion of paraffins to aromatics by Pt particles inside the small pores of silicalite was not thought to be shape-selective since the selectivity was similar to that on amorphous supports; however, slow diffusion of aromatic products lead to higher hydrogenolysis rates and, thus, more benzene and toluene. There are six papers in section devoted to conversion of monocyclic aromatics. There is general agreement that shape selectivity leads to paraselective primary products and that reducing the acid strength and number of external acid sites increases the final product selectivity. These conclusions and results are similar to many previous studies in the literature. The largest section of this book is seven papers on the conversion of polycyclic aromatics hydrocarbons. While shapeselective effects are observed in medium pore zeolites for substituted benzenes, several papers demonstrate that for polycyclic compounds larger pore zeolites are generally required. For many reactions, dealuminated mordenite is generally the most selective catalyst. As with monocyclic aromatic compounds, transition-state shape selectivity leads to paraselective primary products and secondary reactions occur at the catalyst surface to lower selectivity. For polycyclic aromatic reactions, the deactivation rate is high, and improvements in catalyst stability are desirable for development of new commercial processes. As with any conference and proceedings, all papers will not be of interest to every reader. However, this collection of review and research papers contains a good balance of general information and current new results to be of interest to most researchers who are interested in zeolites and molecular sieves as catalysts or supports. For those unfamiliar with shape selectivity and the factors which control the product selectivity, these papers present and excellent overview with many good examples. For those already familiar with the extensive literature on shape selectivity, few new concepts emerge. However, this volume summarizes the current research activities on selective hydrocarbon transformations and is a valuable addition to your personal library. Jeffrey Miller, Amoco Research Center, E-1F 150 W. Warrenville Road Naperville, IL 60566-7011 EF000121K 10.1021/ef000121k