Other Commercial Catalyst Formulations

Other Commercial Catalyst Formulations. Many papers and patents have recently appeared which are also addressed to the problem of maintaining mechanical strength as well as activity and chemical stability during steam reforming and methanation. Hence, only selected examples will be given in the following paragraphs. 

Paterson, and Williams of British Gas have described951 the preparation and properties of a coprecipitated Ni-Al203 catalyst (50 wt% Ni) to which were added 1.0 wt% of an alkali metal and 0.5 wt% of ruthenium. This material was shown to have desirable properties when used for the steam reforming of a hydrocarbon oil in the temperature range 410-476 °C. It is, however, not very likely that such a catalyst will be used commercially because of the high cost of ruthenium and the limited supplies of this metal which are available. Another British Gas patent, referred to previously, introduces chromium into the formulation to improve the stability of the resultant catalyst.77 

Funabiki, T. Iwana, and T. Sezume, Jpn. Kokai Tokkyo Koho, 79 119 385. 

Funabiki, M. Suehiro, andT. Sezume, J. Chem. Soc., Faraday Trans. 1, 1979, 75, 787. 

Suehiro, Y. Saito, T. Miyake and Y. Takegami, Appl. Catal., 1982, 2, 389. 

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The conventional nickel-based catalysts could be modified by adding oxide promoters such as potassium, lanthanam, cerium, and molybdenum in the catalyst formulations. It is believed that the added promoters improve the dispersion of nickel metal on the catalyst surface, thereby reducing the chance of carbon accumulation. Noble metals such as Pd, Pt, Ru, and Ir have been found to be more carbon tolerant as the solubility of carbon is less in these metals.54-57 However, they are more expensive than nickel-based catalyst, and as a consequence, they are less attractive for large-scale commercial applications. Alloying of nickel with other base metals such as Cu, Co, or noble metals such as Au, Pt, and Re has also been found to decrease... 

In this section we will discuss an example of recent laboratory work on the impact of sulfur on palladium catalysts formulations compared to other noble metal formulations. The laboratory studies discussed here have been performed using an apparatus which simulates the exhaust gas generated from a vehicle under several operating modes. The simulated exhaust gas is then heated to a controlled level and directed to a sample core taken from a commercial automotive converter. Quantitative analysis of pollutant and other gas species (CO, HC, NOx, COj and Oj) is performed using gas bench analyzers prior to and following the catalyst sample to determine the conversion efficiency for HC, CO and NOx. 

Research supporting the development of a compact water gas shift (WGS) reactor subsystem included catalyst screening studies, kinetic model development, and test reactor design and performance evaluation. Water gas shift catalysts obtained from commercial and other developers were converted into an engineered form and tested versus temperature, space velocity, and steam-to-gas ratio in single-channel reactors. Both base metal and precious metal catalyst formulations were included in the studies. 

This catalytic ammoxidation process was truly revolutionary. Since the introduction of this technology, INEOS has developed and commercialized several improved catalyst formulations. These catalyst advancements have improved yields and efficiencies vs. each prior generation to continually lower the cost to manufacture acrylonitrile. INEOS continues to improve upon and benefit from this long and successful history of catalyst research and development. In fact, many of INEOS s licensees have been able to achieve increased plant capacity through a simple catalyst changeout, without the need for reactor or other hardware modifications. INEOS s catalyst system does not require changeout overtime, unless the licensee chooses to introduce one of INEOS s newer, more economically attractive catalyst systems. 

Such chemical interactions have prompted extensive investigations of the influence of support materials on overall catalytic behaviour in many systems, and have extended considerably the range of mainly oxide materials used as supports in commercial catalysts. In many systems the so-called support material is thus an important part of the complete catalyst formulation, fulfilling a dual role, though usually retaining crystallographic identity except at boundaries with other components. 

The partially trlmerizedi soluble resins can be blended with other resins> catalysts additives etc. to formulate commercially acceptable coatings adhesives laminates and structural composites. 

The oxidation of NH3 occurs on Fe-exchanged catalysts and contributes to less than 100 % conversion of NOx at high temperature due to the consumption of the reductant. Figure 11.3 compares a commercial Fe-zeoUte catalyst with an as-synthesized Fe-ZSM-5 catalyst (18 wt.% washcoat loading) in the absence of water in the feed. The two catalysts give nearly identical results. The addition of 2 % H2O in the feed leads to a modest decrease in the NO conversion for the commercial catalyst. As we show later, this modest Fe activity can be exploited in dual component SCR catalyst formulations in which the other metal (Cu) is a much more active ammonia oxidation catalyst. 

Regarding the co-catalytic role of Sn for methanol oxidation, on the other hand, the experimental evidence is less conclusive compared to the case of CO oxidation. Colmati et al. prepared PtSn/C catalyst formulations (9 1 and 3 1 atomic ratio) using formic acid reduction and compared the activity with commercial (E-TEK Inc.) Pt/C and PtSn (3 1)/C, including DMFC foel cell experiments [79]. Unfortunately, no comparison with PtRu was presented. Employing 0.4 mg cm anode catalyst load and 3 atm O2 pressure, the maximum fuel cell power output at 343 K was obtained with PtSn (3 1) produced by the formic acid method, 400 mW... 

Diperoxyketals, and many other organic peroxides, are acid-sensitive, therefore removal of all traces of the acid catalysts must be accompHshed before attempting distillations or kinetic decomposition studies. The low molecular weight diperoxyketals can decompose with explosive force and commercial formulations are available only as mineral spirits or phthalate ester solutions. 

More recently there have been developed water- resistant phosphorus-based intumescence catalyst. This commercially available product, as an example Phos-Chek P/30 tradename from Monsanto, can be incorporated (with other water insoluble reagents) into water-resistant intumescent coatings of either the alkyd or latex-emulsion type. These intumescent coatings, formulated ac-... 

Ammonium polyphosphates, on the other hand, are relatively water insoluble, nonmelting solids with very high phosphorus contents (up to about 30%). There are several crystalline forms and the commercial products differ in molecular weights, particle sizes, solubilities, and so on. They are also widely used as components of intumescent paints and mastics where they function as the acid catalyst (i.e., by producing phosphoric acid upon decomposition). They are used in paints with pentaerythritol (or with a derivative of pentaerythritol) as the carbonific component and melamine as the spumific compound.22 In addition, the intumescent formulations typically contain resinous binders, pigments, and other fillers. These systems are highly efficient in flame-retarding hydroxy-lated polymers. 

On balance, palladium offers the best combination of activity and selectivity at reasonable cost, and for these reasons has become the basis of the most successful commercial alkyne hydrogenation catalysts to date. Because of their inherently high activity, these catalysts contain typically less than 0.5 % (by weight) of active metal-to preserve selectivity at high alkyne conversion. Despite the prominence of these catalysts, other active metals are used in fine chemicals applications. Of particular utility is the nickel boride formulation formed by the action of sodium borohydride on nickel(II) acetate (or chloride). Reaction in 95 % aqueous ethanol solution yields the P2-Ni(B) catalyst and selectivity in alkyne semi-hydrogenation has been demonstrated in the reaction of 3-hexyne to form cw-3-hexene in 98 % yield [15,16] ... 

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