Magnesium oxide catalyst

Kolbel et al. (K16) examined the conversion of carbon monoxide and hydrogen to methane catalyzed by a nickel-magnesium oxide catalyst suspended in a paraffinic hydrocarbon, as well as the oxidation of carbon monoxide catalyzed by a manganese-cupric oxide catalyst suspended in a silicone oil. The results are interpreted in terms of the theoretical model referred to in Section IV,B, in which gas-liquid mass transfer and chemical reaction are assumed to be rate-determining process steps. Conversion data for technical and pilot-scale reactors are also presented. 

Cunningham et al (63) have studied the rate of hydrogenation of ethylene at 1 atm on a copper-magnesium oxide catalyst. They used flow reactors to study the reaction kinetics over both finely divided catalyst particles and spherical... 

Cunningham, Carberry, and Smith [AIChE J., 11 (636), 1965] have studied the catalytic hydrogenation of ethylene over a copper-magnesium oxide catalyst. 

NMR properties, 33 213, 274 in NMR studies of zeolites, 33 254-264 in sheet silicate studies, 33 342-345 -magnesium oxide catalyst, lattice parameter, 35 75... 

Two series of catalysts were synthesized for subsequent evaluation as methane dimerization catalysts. The first series was alkali modified zinc oxide (6) and magnesium oxide catalysts (7), which were reported to be active for methane activation, while the second series was ion modified perovskites described by Machida and Enyo (8). The objective of the present study was to determine whether the aerosol technique could provide a wide range of ion substitutions as homogeneous solid solutions, and to determine whether moderately high surface area catalysts could... 

For various types of catalyst there are results of kinetic investigations for the oxidative dehydrogenation of ethane available (e.g., for a magnesium oxide catalyst doped with samarium oxide, lithium nitrate and ammonium chloride [64] or a V2O5/Y-AI2O3 catalyst [68]). In another study with a Sn.oLai.oNdi.oOx catalyst, investigations were reported of noncatalytic reactions, which were found to be significant at temperatures above 700 °C [69]. 

Wang JX, Lunsford JH. Characterization of [Li+O] centers in lithium-doped magnesium oxide catalysts. J Phys Chem. 1986 90 5883-7. 

Ito T, Wang J, Lin CH, Lunsford JH. Oxidative dimerization of methane over a lithium-promoted magnesium oxide catalyst. J Am Chem Soc. 1985 107 5062-8. 

Ueda et al. (37) have proposed magnesium oxide catalyst modified with a transition metal ion (M/MgO) for the vinylation of methyl propionate and acetonitrile. Acetonitrile is vinylated to acrylonitrile selectively (94% selectivity at about 10% conversion) over Cr/MgO catalysts at 350 C in the absence of oxygen. The selectivity for the vinylation of methyl propionate over Mn/MgO catalysts is not different from the value obtained with Ti -TSM in the presence of oxygen. The catalyst system, however, is not effective for the reaction of acetic acid. We conducted the reaction of acetonitrile and methanol over Ti -TSM in the presence of oxygen, and found that the vinylation does not take place but the hydrolysis to acetic acid and subsequent esterification with methanol into methyl acetate proceed preferentially. It is likely that Ti -TSM is an appropriate catalyst for the vinylation of carbonyl compounds and M/MgO is appropriate for the vinylation of nitriles. 

Example 2-1 Wynkoop and Wilhelm studied the rate of hydrogenation of ethylene, using a copper-magnesium oxide catalyst, over restricted pressure and composition ranges. Their data may be interpreted with a first-order rate expression of the form r = (ki)pPH (A)... 

OXIDATIVE COUPLING OF METHANE OVER PROMOTED MAGNESIUM OXIDE CATALYSTS RELATION BETWEEN ACTIVITY AND SPECIFIC SURFACE AREA... 

Recently Ito and Lunsford [ref.l] have shown that ethane and ethylene can be obtained directly from methane by oxidative coupling (0XC0) using a lithium-proinoted magnesium oxide catalyst. CSIRO, in collaboration with The Broken Hill Proprietary Company Limited (BHP), is conducting research on oxidative coupling to determine the feasibility of using this technique in the commercial production of liquid fuels from natural gas. 

The efficiency of zinc-chromium and vanadium-magnesium oxide catalysts in the reaction of butanediol dehydrogenation has been established. The optimum reaction conditions in butadione synthesis providing high yields and selectivity have been found. Experimental substantiation of principles for the purposeful synthesis of the catalytic systems mentioned above is considered. The catalysts were prepared based on these principles. 

We have investigated a series of the dehydrogenating catalysts for this reaction. Our attention was focused on two of them. Further study of 2,3-butanediol dehydrogenation and oxidative dehydrogenation to butadione was performed using zinc-chromium oxide catalysts and vanadium-magnesium oxide catalysts as well. 

Table 1 presents the properties of vanadium-magnesium oxide catalysts subjected to the heat treatment. The temperature of the heat treatment determines both the textural and the catalytic properties of the catalyst. Similar to the dehydrogenation of ethylbenzene into styrene [10,11], the most active catalysts occurred to be those... 

Surface composition and reactivity of lithium-doped magnesium oxide catalysts for oxidative coupling were studied recently by Peng et al. Two lithium phases were observed on the surface. Also, as noted by Lee and Oyama, this lithium-doped magnesium oxide catalyst appears to be the only one for which the methane activation sites have been identified. 

According to Malinowski and co-workers (48), the reactivity of acetaldehyde, acetone, and acetonitrile, respectively, in the condensation with formaldehyde on a magnesium oxide catalyst at 300° is proportional to the acidity of these compounds measured in aqueous solution at room temperature. Figure 8 shows these data in the form... 

In the context of heterogeneous asymmetric catalysis, Choudary et al. " reported a recyclable heterogeneous nanocrystalline magnesium oxide catalyst for the AH and AM reactions to afford chiral nitro alcohols and Michael adducts in good to excellent yields and enantioselectivities (ee s) (Scheme 5.1). 

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