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The benzene methylation with methane over zeolite catalysts was previously shown in our laboratory to require the presence of oxygen. Thus, a two-step mechanism involving the intermediate formation of methanol by partial oxidation of methane followed by the methylation of benzene with methanol in the second step, was postulated. This paper now reports the results of the characterisation of the zeolite catalysts used for the oxidative benzene methylation reaction in order to provide some information about their composition, structure, properties and their behaviour before and after the reaction. The catalysts were characterised by X-ray diffraction (XRD), inductively coupled plasma atomic emission spectroscopy (ICP-AES), X-ray fluorescence (XRF), FT-IR and solid state NMR. XRD results indicate that the crystalline structures of all the ZSM-5 and H-beta catalysts remained unchanged after batch reaction of benzene with methane over the catalysts in agreement with the observation that the catalysts recovered from the reactor could be reused without loss of activity. Elemental analyses and FT-IR data show that as the level of metal ion exchange increases, the Brönsted acid concentration decreases but this metal ion exchange does not totally remove Brönsted acidity. FT-IR results further show that only a small amount of acid sites is actually necessary for a catalyst to be active since used catalysts containing highly reduced Brönsted acidity are found to be reusable without any loss of their activity. 29Si and 27Al magic angle spinning (MAS) NMR together with FT-IR spectra also show that all the active zeolites catalysts contain some extra-framework octahedral aluminium in addition to the normal tetrahedral framework aluminium. The presence of this extra-lattice aluminium does not, however, have any adverse effect on the crystallinity of the catalysts both before and after oxidative benzene methylation reaction. There appears also to be no significant dealumination of the zeolite catalysts during reaction since their catalytic performance was retained after use.

We have previously shown in our previous investigations that the presence of oxygen is required for the benzene methylation with methane over zeolite catalysts in a high pressure batch reactor. Thus, a two-step mechanism involving the formation of methanol intermediate by methane partial oxidation followed by benzene methylation with methanol in the second-step was postulated. This paper now presents the results of further investigation that provide more evidence that the catalytic benzene methylation with methane does occur and that the reaction is limited by the amount of oxygen. Further support is therefore given to the two-step oxidative reaction mechanism. Suggestions for further work in this area are also given. (C) 2003 Elsevier B.V. All rights reserved.

The methanol to aromatics conversion is shown to contribute significantly to the benzene methylation with methanol at 400degreesC over acidic ZSM-5 catalysts but such contribution over all catalysts is negligible at 250degreesC. Benzene-only conversion shows only negligible contribution at both temperatures over the catalysts studied. However, it appears that the methanol-only conversion can be minimised, to enhance the benzene methylation with methanol (and indirectly the oxidative benzene methylation with methane), by using NaZSM-5 with highly reduced Bronsted acidity. (C) 2002 Elsevier Science B.V. All rights reserved.

The methylation of toluene with methane in the presence of oxygen over zeolite catalysts is shown to be complicated by extensive disproportionation, hydrodealkylation, and hydrocracking reactions. However, it appears that these undesired reactions can be minimized, to enhance the methylation reaction, by using zeolites with reduced Bronsted acidity.

Trace amounts of ethylene impurities in the methane used for benzene methylation over ZSM-5 and H-beta catalysts are found to enhance benzene conversions and selectivity to ethylbenzene. However, methane containing ethane impurities yielded negligible benzene conversion in the absence of oxygen over CoZSM-5 while a much higher conversion is obtained over H-beta due to cracking of benzene as previously reported.

Previous studies in this laboratory have shown oxygen to be a crucial requirement for the reaction of methane with benzene over zeolite catalysts at 400°C in a high pressure batch reactor. Thus, a two-step mechanism involving the intermediate formation of methanol by partial oxidation of methane followed by the methylation of benzene with methanol in the second step, was postulated. This paper now shows clearly that there is excellent correlation between the performance of the zeolite catalysts used for the methylation of benzene with methanol in a low pressure flow reactor and the methylation of benzene with methane in the presence of oxygen in a high pressure batch reactor. This finding therefore gives further support to the two-step mechanism for the oxidative methylation reaction at 400°C.

The methylation of benzene with methane over ZSM-5 zeolite catalysts in a high pressure static reactor is shown to require oxygen as a reactant, implicating methanol as a key intermediate species. In the case of zeolite H-beta, methyl aromatics can be formed in the absence of oxygen, consistent with an earlier report that these products are formed from cracking of benzene over the acid zeolite.

This paper describes characterization studies of Mo-HZSM-5 zeolite catalysts active for the non-oxidative conversion of methane to benzene. FTIR, 27 Al and 29 Si NMR evidence is presented for migration of molybdenum into the zeolite pores during catalyst calcination at high temperatures. Mo K-edge EXAFS confirms that calcination produces highly dispersed oxomolybdenum or molybdate species which are converted to a molybdenum carbide phase under reaction conditions. Factors determining catalyst performance are discussed.

The reactivities of Australian coals and one American coal with methane or methane-hydrogen mixtures, in the range 350–400°C and a range of pressures (6.0–8.3 MPa, cold) have been examined. The effects of aluminophosphates (AlPO) or zeolite catalysts, with and without exchanged metals, on reactivity have also been examined. Yields of dichloromethane extractable material are increased by using a methane rather than a nitrogen atmosphere and different catalysts assist dissolution to various extents. It appears that surface exchanged catalysts are effective, but incorporating metals during AlPO lattice formation is detrimental. Aluminium phosphate catalysts are unstable to water produced during coal conversion, but are still able to increase extraction yields. For the American coal, under methane-hydrogen and a copper exchanged zeolite, 51.5% conversion was obtained, with a product selectivity close to that obtained under hydrogen alone, and with only 2% hydrogen consumption. The conversion under methane-hydrogen was close to that obtained under hydrogen alone, while a linear dependence of conversion on proportion of methane would predict a 43% conversion under methane-hydrogen. This illustrates a synergistic effect of the methane-hydrogen atmosphere for coal liquefaction using this catalyst system.

The experimental conditions which control the exchange from deuterium or tritium gas into the C-1 proton position of glucose in aqueous solution have been studied in detail, with a view to determining the factors which maximize exchange into glucose, but minimize exchange into the solvent water. The favoured conditions for producing glucose with close to 100% isotope labelling in the C-1 position, and with negligible formation of labelled byproducts, were a reaction time of 6 to 8 hours, a temperature of 60°C, and a pH of 7 or higher. Pd/BaSO 4 was the preferred catalyst and slow pre-addition of the deuterium or tritium gas to the catalyst bed was essential to maximize the subsequent isotope exchange into the substrate.

An isotopic study utilizing methane- 13 C shows that the product toluene and xylenes formed from its reaction at high pressure (5.5 MPa, 400 °C) with benzene, over Cu/beta and H-beta zeolites, contain substantially methyl- 13 C substituents. It is therefore concluded that direct methylation of benzene with methane is possible under these conditions in a batch reactor. However, a second mechanism can also be recognized in which methylbenzene is formed by fragmentation and rearrangement of benzene without addition of methane gas.

A range of organic substrates was successfully exchanged with tritium gas using NaBH4-reduced palladium oxide or chloride as catalyst. Exchange conditions involved a reaction temperature of 100 °C, a reaction time of 3 days, and products were analyzed by radio-gas chromatography and 3H NMR spectroscopy. Both aromatic and aliphatic compounds underwent exchange, 18 of the 22 substrates incorporated > 35% of the available tritium, and most products showed high radiochemical purity. 3H NMR analyses showed that both alkanes and the alkyl chains of alkylbenzenes were rapidly and evenly labelled. Some aromatic compounds showed general ring exchange while others showed high specificity. These results for bulk palladium catalyst are strikingly different from those obtained with bulk platinum and supported palladium catalysts. The results are discussed in terms of currently accepted mechanisms of heterogeneous metal catalyzed hydrogen isotope exchange reactions.

Platinum-loaded microporous aluminophosphate molecular sieves (Pt-AlPO4-5) were synthesized and studied as catalysts for promoting tritium isotope labelling by exchange between tritium gas and aromatic, heteroaromatic and aliphatic hydrocarbons. The presence of the Pt metal considerably enhanced the activation of the tritium gas. Detailed isotope orientation patterns, as determined by 3H nmr spectroscopy, showed that the AlPO4-5 component of the catalyst dominated the exchange reactions, but some influence of the Pt metal was apparent with some substrates.

A synthesis of [3H]R- and [3H]S-4-amino-3-phenylbutanoic acid ([3H]R- and [3H]S-β-phenylGABA) from the unsaturated intermediate by catalytic hydrogenation using tritium gas in the presence of palladium on charcoal is reported. The [3H]R- and [3H]S-diastereoisomers of pantolactone ester of β-phenylGABA were separated by HPLC.

A synthesis of [3H]E- and [3H]Z-4-aminobut-2-enoic acids from methyl 4-N-phthalimidobut-2-ynoate by catalytic hydrogenation using tritium gas in the presence of a homogeneous catalyst, tris(triphenylphosphine)rhodium(I) chloride, is reported. HPLC separation of the E- and Z-isomers, and the saturated analogue, 4-aminobutanoic acid (GABA), is also described.

Microporous AlPO4-5 catalysts exhibit catalytic activity for tritium isotope exchange and other reactions but the activity of the catalyst may vary widely from one batch of catalyst to another although all catalyst samples appear to show pure AlPO4-5 phase. This catalytic activity appears to correlate with the presence of octahedral aluminium in the catalyst samples as revealed by solid sate 27Al NMR spectroscopy and this is attributed to defect sites in the lattice. The exchange patterns may show high regional specificity. These patterns have some of the features of acid catalysis but are assumed to be modified by the constraints imposed by the micropore geometry.

The catalytic activity of substituted aluminophosphate molecular sieves, ElAPO-5 (El=Pb, Cu, Ni, and Si), in the activation of methane for direct methylation of naphthalene has been investigated at 400 ° C under elevated pressures of methane in an autoclave. In the presence of the as-synthesized catalysts, methylation of naphthalene was observed by gas chromatography and 1 H NMR spectroscopy. The major identified products in the methylation experiments were the two monomethylnaphthalenes together with small amounts of ethyl and dimethylated products and dinaphthalene. CuAPO-5, PbAPO-5, and SAPO-5 gave conversions of 15-16% in 1 h, whereas NiAPO-5 showed lower activity. Based on the naphthalene remaining, up to 21% naphthalene conversion was obtained when a catalyst incorporating both Cu and Si was used

The first application of tritium NMR spectroscopy to the direct observation of proton-exchange kinetics is described; this technique allows the study of milligram amounts of substrates and for substrates with multiple exchangeable positions. The examples include benzene and the ring and methyl positions of p-xylene reacting with cesium cyclohexylamide in cyclohexylamine, and the enolate positions of cyclohexanone and methyl 7,12-dihydroxy-3-ketocholan-24-oate reacting with heptafluorobutyric acid in dioxane.

A wide range of simple organic substrates has been successfully tritium labelled using reduced platinum oxide as catalyst. Exchange conditions involved reaction temperatures in the range 60–150°C, and reaction times of 3–7 days. The isotope sources for the reactions were tritium gas and tritiated water. Analysis of the labelled products was accomplished by radio‐glc and by H NMR spectroscopy. The specific activities ranged up to 1100 mCi/mL, and most of the labelled products showed high radiochemical purity. The regioselectivity of tritium incorporation, as obtained from H NMR studies, supports currently accepted theories for mechanisms of platinum‐catalyzed hydrogen isotope exchange. The results also show remarkable consistency for a heterogeneous system under widely varying reaction conditions.

Publisher Summary The utilization of natural gas as a hydrogen rich reagent, in place of hydrogen itself, for direct coal liquefaction at pyrolysis temperatures would have considerable economic advantage, because a high proportion of the cost of the hydrogenation of coal is in the production of the hydrogen itself. It is well known that methyl radicals generated in other ways do cap the radicals formed in coal pyrolysis and hence decrease the proportion of coke formation. For this reason a study of the ability of methane to methylate aromatic compounds which may be taken as models for coal is being studied using substituted aluminophosphate molecular sieves as catalysts. There have been a few isolated claims in the literature that methane can be catalytically activated over metal substituted AlPO's at around 400°C and a few patents have been issued. The work of Iton and co-workers is one such example where it was claimed that cobalt-substituted AlPOs have the capacity to oxidatively homologate methane to higher hydrocarbons at temperatures below 400°C. The thermodynamics of the methylation of aromatics by methane under high methane pressure regimes has been considered, and a variety of silicon lead and copper modified APO 4 -5 catalysts have been tested for their catalytic activity in the methylation of naphthalene, toluene and phenol.

Hydrogen isotope exchange of nitrobenzene with tritium gas and tritiated water is studied over heterogeneous and homogeneous forms of platinum, palladium and nickel. Exchange with water is facile where homogeneous platinum and palladium salts are the catalysts but this is not the case over heterogeneous forms of the metals. In contrast, exchange with tritium gas is facile over heterogeneous platinum, palladium and nickel. Exchange in nitrobenzene is thus an indicator of homogeneous, as distinct from heterogeneous, exchange as previously claimed, only where the isotope source is water and not elemental hydrogen. Detailed isotope orientation patterns, determined by 3H NMR, are interpreted in terms of the type of absorption intermediate on the metal, and compared with those of aniline.

Hydrogen isotope exchange between deuterium gas and protium in hexane, pentane, 2-methylbutane, 2-methylpentane, 3-methylpentane, 2,3-dimethylbutane, and 2,4-dimethylpentane has been catalyzed by clean platinum films (70–100 °C). A selection of these reactions has been catalyzed by films of rhodium and iridium (typically −13 to −35 °C). In all cases, multiple exchange occurred. Product analysis by mass and proton NMR spectroscopy showed that exchange in methylene and methine groups was more rapid than that in methyl groups. A similar orientation effect was observed in reactions over platinum powder but not over platinum-alumina. For exchange between deuterium oxide and hexane catalyzed by platinum films at 200 °C, the rate of exchange in methyl groups exceeded that in methylene groups. It is proposed that preferential exchange in methylene and methine groups is normal behavior during alkane exchange with molecular deuterium over these platinum metals when their surfaces (i) are initially clean or (ii) contain several adjacent sites which are unperturbed by the presence of any electronegative adsorbed species. In these cases, multiple exchange may occur via the interconversion of CnH2n + x (ads) and CnH2n + x − 1(ads), where x is probably 1, but may be zero or negative. Preferential exchange in the methyl groups of hexane results from contamination of the surface by adsorbed D2O, OD, or O; this may be a geometric effect or an electronic effect, depending on the magnitude of the surface coverage of water, which is unknown. It is proposed that, under these circumstances, alkane is adsorbed as a charge-transfer state, and multiple exchange occurs via the interconversion of CnH2n + 2(ads) and CnH2n + 1(ads) in a manner analogous to that proposed earlier for catalysis by chloroplatinate ion in deuterated solvent. Orientation in the exchange between deuterium gas and naphthalene or biphenyl catalyzed by films of platinum and iridium does not differ from that observed in exchanges where the isotope source is deuterium oxide or deuterated solvent, but the M value calculated for exchange in naphthalene is higher than that previously reported.

In the simultaneous irradiation procedure, sensitized W radiation is shown to be a complementary initiator to ionizing radiation for the grafting of monomers to polyolefins. Parameters influencing the yield of graft have been considered, including the role of sensitizer, solvent, and the type of monomer. These results indicate why difficulties have been experienced by previous authors in photografting monomers to polymers using analogous procedures. Grafting of styrene to cellulose acetate using ionizing radiation at low total doses is also reported. Difficulties associated with the poor grafting yield to gel beads as opposed to films are considered predominantly in terms of moisture content and swelling of the gel beads. The feasibility of using the polyolefins and cellulose acetate beads modified by the present grafting methods in reagent insolubilization reactions is discussed.

Levamisole (LEV) is a widely used anti-parasitic agent. In order to characterise the biochemical pharmacology of LEV in parasitic nematodes, [3H]LEV and a more active analogue [3H]m-aminolevamisole (MAL) have been prepared. Labelling was accomplished by tritiated water exchange of MAL under acid conditions. Multiple site labelling was achieved in the positions ortho and para to the amino group of MAL. Tritiation of MAL HCl in [3H]2O was achieved at 103°C for 23 h. Crude [3H]MAL was diazotised (hydrochloric acid and sodium nitrite) and deaminated (hypophosphorous acid) to effect the synthesis of [3H]LEV. Products of both reactions were purified by preparative h.p.l.c. and characterised by h.p.l.c., t.l.c. and mass spectrometry. (Radiochemical yield was about 15% and purity >90%.) Specific activities of 39 Ci/mmol for [3H]MAL and 37 Ci/mmol for [3H]LEV were obtained.

The tritiation of a range of low molecular weight alkanes and alkenes has been investigated by self-radiation induced exchange with HTO at room temperature and 115°. By comparison with the Wilzbach T2 gas exposure procedure, the HTO method yields less byproducts and radiochemical purification of the parent compound is facilitated. With alkenes, saturation of the double bond is a competing process in the HTO procedure, however the significance of this side reaction decreases with increasing temperature of exchange. The HTO technique is shown to be suitable for tritiating a wide range of hydrocarbons to medium levels of specific activity.

Mineral acid and polyfunctional monomers in additive amounts (1% v/v) are shown to act synergistically in enhancing radiation grafting yields for a typical system involving the copolymerization of styrene in methanol to the polyolefins. Polyethylene and polypropylene films have been used as representative backbone polymers with divinylbenzene and trimethylol-propane triacrylate as typical polyfunctionals in the current work. The effect of dose rate on the copolymerization yield is reported. Grafting efficiency is shown to be enhanced in the presence of both additives. A theory for the role of additives is proposed. The synergistic effect also operates with polypropylene powder. Such an observation is shown to be important in applications of these copolymers for enzyme immobilization, heterogenization of catalytically active homogeneous metal complexes, insolubilization of analytical reagents and art restoration.

Comparaison de H 2 SO 4 et LiClO 4 comme additifs dans le greffage photochimique du styrene dans le methanol sur la cellulose et sur un film de polyethylene; comparaison des rayonnements UV et ionisants comme amorceurs pour le greffage du styrene au polyethylene en presence d'additifs acide et sel

Deuterated analogues of various phenolic steroids, catechols and indole derivatives were prepared in high chemical yield by heating the relevant compound in D2O at 190°C for 24 hours.

A method for the synthesis and purification of mebendazole specifically labelled with tritium in the 4′ position is described.

Boron tribromide has been assessed as a catalyst for rapid tritium labeling of organic compounds using tritiated water under mild conditions. Alkyl and halogen substituted aromatics labeled rapidly, the labeling being most pronounced in the ortho and para positions. Compounds containing electrophilic deactivating groups were found to be difficult to label. Very little byproduct formation was observed.

The effect of solvent structure, particularly the application of the low molecular weight aliphatic alcohols, on the radiation grafting of monomers to PVC with the use of cobalt-60 and the simultaneous procedure is discussed. The addition of sulfuric acid to a typical system such as styrene/methanol/PVC enhances both the grafting yield and the size of the Trommsdorff peak. The results are shown to be consistent with a mechanism involving charge-transfer complex formation between monomer and grafting site in PVC. The role of hydrogen atoms in these reactions, particularly in the presence of sulfuric acid, is emphasized, and the importance of the magnitude of G(H) on the grafting yields and the Trommsdorff effect is discussed. These principles, developed for radiation grafting styrene, are shown to be of value for the radiation copolymerization of p-nitrostyrene and vinyl phosphorus monomers to PVC. The use of these PVC copolymers for immobilizing enzymes such as trypsin and heterogenizing typical ...

A 220 MHz proton n.m.r. spectrum of 2,2′-bipyridyl in a nematic phase solution has been analysed to yield a set of dipolar coupling constants, Dij. The couplings Dij are not in complete agreement with a description of the molecule as a single conformation. The trans-form alone occurs in solid, 2,2′-bipyridyl, but although this is probably the predominant form in the liquid state, there does appear to be a difference between the molecular structure in the two phases.

Adaptation du second detecteur d'ionisation de flamme d'un chromatographe gazeux a deux detecteurs, pour en faire une chambre d'ionisation

A practical synthesis of [14-3H]dibenz[a,j]acridine and [7-3H]dibenz[a,h]acridine is reported from the parent hydrocarbon by catalytic exchange with tritium gas in the presence of palladium on calcium carbonate. Analogous regiospecific labelling with deuterium was also affected. In addition [14-14C]dibenz[a,j]acridine was prepared from [14C]paraformaldehyde.

Benzimidazole carbamates (BZCs) act as inhibitors of the tubulin-microtubule equilibria in eukaryotic organisms. Recently drug resistance to this class of compounds in helminth parasites has been shown to be due to a reduced ability of resistant tubulin to bind BZCs. In order to quantitate the nature of the tubulin-BZC interaction a general method for the specific tritium labelling of BZCs has been developed. The BZCs: mebendazole, oxfendazole, parbendazole, oxibendazole, albendazole and fenbendazole were labelled by catalytic exchange using palladium on calcium carbonate in pure dioxane at 60°C under tritium gas. The position of label incorporation for tritiated albendazole was determined by tritium-NMR as the 4-position of benzimidazole nucleus. The yields for individual BZCs varied from 8 to 68% for a range of specific activity of 0.44 to 13.4 Ci/mmole.

Results of studies of ..gamma..-induced grafting of p-styryl diphenyl phosphine (SOP) to polyvinylchloride (PVC), polypropylene and crosslinked polystyrene beads are described. SOP dissolved in dioxane-methanol radiation grafts readily to PVC at close rates up to 1.5 Mrad, and a Trommsdorff peak was observed at about 28% v/v monomer concentration under experimental conditions set forth here. SOP was found to be much more efficient in radiation grafting than vinyl phosphine. A photosensitized process using uv radiation was also investigated, and SOP was found to copolymerize easily to PVC and crosslinked polystyrene. The copolymerized SOP is useful for attachment of metal ions to yield catalysts suitable for hydrogenation reactions. Data for hydrogenation of cyclohexane using such catalysts showed as much as 30% conversion of the cyclohexane using chlorocarbonyltris(triphenylphosphine) iridium as catalyst. (BLM)

Additives which can increase the yield in the radiation grafting of monomers to polymers are useful. The use of polyfunctional monomers as additives (approx. = 1% v/v) are shown to enhance significantly the copolymerization yields of styrene in methanol to films of polyethylene and polypropylene under certain radiation conditions. The results obtained when the polyolefins are replaced by PVC as backbone polymer in these accelerated grafting reactions are reported. Divinylbenzene (DVB) and trimethylolpropane triacrylate (TMPTA) were used as representative polyfunctional monomers for the enhancement effect. When polypropylene was used as backbone polymer, the inclusion of DVB significantly enhanced the radiation grafting of styrene in methanol at all monomer concentrations studied above 35%. At certain monomer concentrations (50% , 60%), the yield of graft copolymer was almost doubled by the addition of DVB. 3 tables. (DP)

Chemical shifts for the aromatic tritons of toluene decrease in the order meta>para>ortho for pure toluene, but in the order meta>ortho>para for dilute solutions of toluene in carbon tetrachloride, chloroform, cyclohexane and dimethyl sulphoxide; m-xylene shifts are 5>4,6>2 in the pure state and 5>2>4,6 in carbon tetrachloride and dimethyl sulphoxide; o-xylene shifts are 4,5>3,6 in the pure state and reversed in carbon tetrachloride.

Radiation grafting is shown to be a method with considerable research and industrial potential for the insolubilization of a wide range of organic reagents on polymer surfaces. The principle of the method is outlined in detail and involves radiation-induced copolymerization of a monomer containing an appropriate functional group to a polymer, then attachment of the reagent by subsequent chemical reactions. The relative merits of the two relevant grafting methods for this purpose, namely pre-irradiation and the mutual technique, are evaluated. Typical experimental procedures for each method are discussed. The mutual technique is shown to be more satisfactory for insolubilization reactions because of the lower radiation doses needed to achieve a particular percentage graft, resulting in less radiation damage to the backbone polymer. Variables influencing the efficiency of the mutual grafting method are reviewed, including solvent, dose rate, and dose. Additives for optimizing the grafting yield and properties are considered, including mineral acid and polyfunctional monomers. Methods for reducing competing homopolymerization are summarized. Three examples of the application of the mutual radiation grafting technique for insolubilization reactions are discussed in detail. These include immobilization of enzymes, heterogenization of catalytically active homogeneous metal complexes, and the anchoring of analytical reagents to form ion exchange resins.

The stereochemistry of the tritiation of L-chiro-inositol, myo-inositol and hexa-O-methyl-L-chiro-inositol by self-radiation induced exchange with tritiated water of high specific activity has been investigated. Predominance of configurational retention was found to accompany tritium labelling in the two inositols, while substantial configurational inversion occurred in the hexa-O-methyl derivative. Tritiation occurred predominantly at C 1 in L-chiro-inositol, with slight inversion at this position alone accompanying the labelling. Comparison with Wilzbach T2 gas exposure results indicates the HTO method yields less by-products, myo-inositol having a radiochemical purity of 97%.

The catalytic oxidation of methane over AlPO4-5 and metal – doped AlPO4-5 has been studied over a range of temperatures (500–900°C) and O2 : CH4 ratios. The major products of the reaction were ethane, ethene, CO2 and H2O. The product distribution was found to be dependent on both temperature and O2 : CH4 Doping of AlPO4-5 with various metals (Pt, Pb, V, Ag, Co, Cu) altered the product distribution, with PbAlPO4-5 the most reactive and selective supported metal catalyst for methane oxidation.