Natural mordenite

Aris A process for the hydrocatalytic isomerization of C8 fractions. Developed by Leuna-Werk and Petrolchemische Kombinate Schwedt in 1976. The catalyst is platinum deposited in a mixture of alumina and natural mordenite. 

Hydrogen-exchanged natural mordenite Hydrocarbon conversion catalyst for the deprotonization of toluene to benzene and xylene... 

Other examples of the use of natural zeolites in catalysis has been the use of Cd-exchanged chabazite, clinoptilolite, erionite, and mordenite as catalysts in the hydration of acetylene to acetaldehyde [26], and a Cu-exchanged natural mordenite, which was studied as a catalyst for the selective reduction of NO with NH3 [27],... 

The data reported in Figure 6.5 indicate that the adsorption process of NH3 in the natural mordenite, MP, is a heterogeneous process. In the plot, a first value at very high energy is evident, which should be related to the acid-base interaction of the NH3 molecule with acidic sites generated in the natural mordenite during the activation [31,49],... 

Liang T., Hsu C., Sorption of Cesium and Strontium on Natural Mordenite , Radiochimica Acta. 61(1993) 105. 

Many more stories can be told in this regard. The chaimel structure of natural mordenite was not foreseen on the basis of sorption experiments because a relatively small number of blockages or dislocations quite adequately blocked the large charmels. In an experiment in my laboratory, sodium LTA failed completely to sorb tetrachloroethylene (both fully anhydrous) because of its size (The crystal structure of a single crystal in an atmosphere of ca 100 torr of C2CI4 for more than a week was exactly that of fully dehydrated LTA.) we should have honored a simple mechanical calculation of size apparently no alternative mechanism existed. In contrast, statements that Cs ions should not be able to enter sodalite cavities in LTA or FAU, have repeatedly been shown crystallographically to be incorrect such entry of Cs" " appears to occur both in the presence and absence of water. 

Cation Exchange in Mordenite. Until 1974 there had been few systematic studies of ion exchange in mordenite and only Rees had determined isotherms. Peculiarities were found which had not been observed in A, X, and Y zeolites or in chabazite, in that only limited exchange of divalent ions could be achieved. Using a natural mordenite from Harbourville, Nova Scotia, Rees found for... 

Site I is in the centre of the highly distorted 8 ring window, and in natural mordenite at least can be occupied by Na, K, and Ca in fully hydrated versions. In hydrogen mordenite any residual Na apparently occupies this site. Sites II,... 

It is rather significant that even after this elegant study, Mortier et al conclude that for natural mordenite they are unable to predict cation occupancy from first principles. 

Free radical methanisms. There has lately been renewed interest in the possibility that free radicals may play a role in the conversion of methanol to hydrocarbons. Zatorski and Krzyzanowskl [8] had earlier proposed a radical mechanism for hydrocarbon formation from methanol over natural mordenite. 

Heteropoly acids [9] and natural mordenite [13] have been previously used in the hydration of camphene with high selectivities to isobomeol. 

Ames [100] studied natural mordenite from Nova Scotia, Canada and concluded that showed selcctivities for monovalent ions as Cs>K>Na>Li and divalent ions Ba>Sr>Ca>Mg. 

Figure 1. Electron diffraction patterns of several mordenite crystals. (A) Natural mordenite from Hicknoi, New Zealand,...

Figure 2. Electron micrographs of several mordenite crystals. (A) Natural mordenite from Hicknoi, New Zealand, (B) Sample 3, (C) Sample 6, (D) Sample 2. In (A) and (B), the main channels are parallel to the length of the crystals, the c axis. In (C), the channels are normal to the plates, which are shown looking down the c axis. The magnifications vary slightly between the micrographs, but are about that shown by the micron scale in (C).

Natural mordenite from Hickuoi, New Zealand. The sample contains less than 5% quartz impurities. Natural mordenite from Lovelock, Pershing Co., Nevada, USA. The sample contains about 20-30% ferrierite and 10-15% feldspar. 

Thus, the position of the T-0 bending band near or below 440 cm correlates well with the presence of faults in these synthetic and natural mordenite crystals, see Table II. 

Natural mordenite has a nearly constant Si/Al molar ratio of 5 and its typical formula can be written as ... 

It is well known that zeolites containing a high proportion of five-membered rings of tetrahedra in their framework are widely used in heterogeneous catalysis these include synthetic ZSM-5, ZSM-11, beta, theta-1, NU-87, the synthetic analogues of natural mordenite and ferrierite and the natural zeolite heulandite. 

The present research is devoted to the study of the physical-ehemical properties of natural zeolites from Armenia. The adsorption of H2, O2, Ar, N2, CO2, SO2 0n natural mordenite from Shirak deposit as well as the adsorption of Ar, N2, SO2 and Xe on Shirak mordenite treated by hydrochloric acid have been studied by volumetric method. The kinetics of O2, Ar and N2 adsorption on natural mordenite have been studied. The isosteric heats of adsorption for H2, O2, Ar, N2, CH4, CO2, SO2, Xe have been measured by chromatographic method. The portion of quadropole interaction has been determined. 

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