The mechanism of heterogeneous catalysis (de Boer, J. H., ed.)

from the major encyclopedias, textbooks and monograms, most of ~ h i e h are pre ... ahout the atom as history and dcvelap- ment of the periodic tahle...
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BOOK REVIEWS chemical properties of the elements and their compounds. He also discusses their reactions and their preparation. Unfortunately most analytical infarmntion is omitted; but even more unfortunate only little or no structural information is inchtded. Another serious drrt~rback is the absence of references, aside from the major encyclopedias, textbooks and monograms, most of ~ h i e hare pre1950. The first volume is divided into two parts, the first of which (111 pages) is an introduction containing such general topics ahout the atom as history and dcvelapment of the periodic tahlefi, clumtum theory, electronic configurations, radioactive deoay, nuclear reactions, the neTr synthetic elements, and htonlio energy. The treatment is condensed and murh important material is left out in line ~ i t h the author's announoed purpose for writing these volumes. The second part of this introduction discusses in about 35 pages the general properties of compounds, including ionic and covalent compounds and their bonding energies, intermetallic compounds, interstitial compounds, hydrates and addition compounds. The second part of the volume considers the nanmmetals and their compounds. In about 500 pages the author discusser the halogens, the oxygen and sulfur group, the nitrogen group, the elements of group IVB (silicon, eta.) and finally t,he compounds of boron. I n all of these groups, he leaves out any discussion of the compounds in these groups containing organic substituents since he wants to include no compounds containing nonmetal or metabcarbon bonds. Criticisms might he directed a t the fact that much of the work reported in the literature in the last five yean has not been included. This volume should be s, good reference book for many scientists in chemistry who do not have copies of Gmelin readily available. I t should be an ezcellent reference book for scientists in the fields of biology, mineralogy, geology, pharmncology and 'possibly even scientists in agriculture. One of its excellent features is the presentation of the physical constants of many compounds in tabular form. This volume is bound in a linen cover, the paper seems to be good but the binding itself is not up to quality.

HANSB. JONASSEN Tulane University New O~leans,Lozrisiana The Mechanism of Heterqenewr

Catalysis Edited by J. H. de Boer, Staatsmijnen im Limburg, Geleen, Netherlands. Elsevier Publishing Co. Distributed in tho U. S. by D. Van h'ostrand Co., Ine., Princeton, New Jersey, 1060. iw 179 pp. Figs. 2nd tsblrs. 13 X 19 cm. 53.

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This small volume constitutes an excellent summary by chemists in Holland of work being done relative to the meehn(Continued on page .l@6)

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BOOK REVIEWS nism of heterogeneous catalysis. I t is rendahle and authoritative. Any chemist wishing to acquaint himself with current problcms in eat,alysis and with the progress that is hoing mad? toward solving t h e e problcms could do no h&er than t o read t,his caerllcnt series of papers and the disrussians t,hat aceompnnird their presentation. T h r introductory chapter hy Professor J. H. de Boer makes rlear the meaning of the word "mechanism" as applied to cnt,slvt,ir rciletions. I t also discusses rhernisarption on catalysts, particularly on met,nllic cat,alysta; the relationship

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of such chemisorption t o the kinetics of catalytic reactions; the mobility of m o l e eules on surfaces and the selectivity of catalysts. A v h y short chapter by Burgers calls attention t,n some recent work in whieh he and his colleagues have found a t least s. qualitntivo relation between the clertronie structure of metal electrodes and redox reactions oceuring a t the electrodes. The next thrcr chapters illustrate in detail some recent work concerning the mechanism of t,hu catalytic decomposition of formic acid and the mechanism of ammonia s,vnthpsi?. These are two renetions whirh rcpeatudly have heen selected for mechanism studics hecause of their s u p p o s ~ d simplirity. The paper by

Fahrenfort, Van Reyen, and Saehtler shows how all of the modern tools of catalytic research can he combined in the study of the mechanism of formic acid decomposition on metals. The interesting conclusion is reached that the reaction proceeds through the formation of mctallic formaten on the catal,vst surfaces. On some metals t h rato ~ of formation of the formate is rate determining; on others, such as nickel, t,he rate of decomposition of the formate appcars to Ire rate determining. This pepcr, i t will b? notrd, leans heavily on the chemical nature of the catalyst in arriving a t a catalytic merhanism. The aclivity of metal oxides for the decom~ositionof formic acid is diseussrd in detail by Mars. A considerable amount of rvidcnce is given to indicate that the activity of oxidw preheated t o the same temperature is related to the charge of the cation and also t o its radius. Fact,ors influrneing the relative amounts of dehydration and dehydrogenation of formic acid far metal oridrs arc dkcussed. The catalytic synth~sis of ammonia over iron catalysts has been known for more than 50 years. I t is therefore with interest that one natm that even at the end of this period there is no unanimity of opinion in regard t o mechanism of this relativrl.~ dean-cut catalytic reaction. Thc paper by Mac?, Srholten, and Zmirtering preseenta some interesting recent results whirh combine t,o support the traditional idea that the slow step in the rate of ammonia synthesis is the rate a t which nitrogr-n is chmiisorhed on metallic iron cntaIysts. However, they also point out t,hat at %hepresent moment thi8 cone~usionas t,o the rate determining step is disputed hy Horiuti and his co-workers in Japan. Hc insists that one of the steps involving the intwactian of hydrogen with nitrogcn, NH, or NHz groups is a slow step of the reaction. The paper is a n encellcnt illust,ration of tho many different. wpronches from which the mechanism of a cat,alytie reaction can he studied. Thc next three chapters are concerned with selective catalytic effects in organic roartions. Hoijtink assoriatcs preferential effects in the hydrogenation of aromat,ic ring compounds such as napthalenc, nnthmcenr, and phcnsnthrene with polarization effects of an elcetrical double layer on the catalyst surface. Xooyman and Van Holden in discussing R new mechanism for the n d l known Zieglrr polymcrizxtion of ethylene suggest that the cthylene moleculas add t o both rnrls of the growing rhains. A c h a p tcr hy Coenrn cslls ntt,ention to the importance of the difhsion processes in the selective hydrogenation of various double hondn in fatty oils. A final chapter hy Keulrmnns and Sehuit diaeusscs proposed mechanisms that have heen used to nrcount for the action of bifunctional catalysts. These lattcr are illustrated hy the platinum hydraforming catalysts that are currenhly used in t,he prodrwtion of high octane gasoline. They c o n k t of a metallic catalyst supported on a solid having sufficient acid sites t o he capable of producing acid catalyzed surface reactions. This hook should he of interest both t,o (Continued on page A@8)

BOOK REVIEWS ~ p e r t in s ratalysis and to those not spreializing in th? subject but interested in a quirk review of eurrent thinking in the field. PAULH. EXMETT Johns Hopkins liniacrsily Baltimore, Jlnlyinnd

Cobalt: Its Chemistry, Metallurgy ond User

Edited by Roland S. Young, Consulting Chrmical Engineer, Victoria, British Columbia. .ICS Monograph 1.0.149. Rrinhold Publishing Corp., New I'orli, 1960. vii 424 pp. Figs. and tahles. 1.53 X 23.5 cm. $15.

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Thc tremendously increased activity in chemistry during the last 15 years has madc necessary the compIct,e rewriting of much of the chemical literature, including the ACS monograph on cobnlt nhieh Dr. Young wrote in 1048. A though the 1980 volume resembles t h e earlier one in sum" mays, it,is not a reviaion, but a really new and much larger book. Many of t h e ehapten have n o eountcrpnrts in the older book; thoso t h a t do hnvc heell completely remittrn and brought up to date. I n thc writing of this volume, Dr. 1-ounk has had the assistance of sevoral specialists who have m i t t e n c h a p t m on the fields in which they are expert. The writing throughout is of uniformly high quality and, odd as it may seem for a technical book, this reviewer had trouble in laying the volume aside. The simple cobxlt(I1) salts are dealt with rather lightly, but t h e othcr mpects of the chemistry, metallurgy and uses of cohnlt are discussed in an interesting and authoritative way. The chemist who wants t o knox about the history of cohalt, t h e optical isomerism of cobalt complexes, t h e mystery of "salt sick" sheep, the 0x0 procm, thc use of cobalt-GO in the diagnosis of pernicious anemia, or the camplicated and interesting chemistry involved in the extraction of cobalt from its ores d l find the answer here. These example are but representative bits taken from ehaptrrs on the history of cobalt, its complexes, its brhnvior in biological processes, its uses in cntalysis, radioactive cobalt, and the extractive metallurgy of the metal. Other chapters are concerned with the ocourrence,properties, andsimplesalts of cobalt, its phase diagrams and alloys, its applientions in magnetic, electric and eleotronie uses, in tool steels, in cemented carbides, and in ceramics, its electrodeposition and its quantitative determination. Every chapter excites the reader's curiosity and suggcsts interesting research problems. Even t h e discussion of the simple salts, h-hichmight he thought to be too elementary to be very thought provoking, reports the amazing observation that cobalt(I1) ic+ dide exists in two isomeric forms, one af (Conlinzted on page ,4600)

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