Hydrogen, properties

Properties of hydrogen Properties of metals Band theory Properties of nonmetals Properties of transition metals Coordination compounds Crystal-held theory Complex ions... 

Both uncalcined and calcined LDHs have also been shown to be effective supports for noble metal catalysts [18-25]. For example, palladium supported on Cu/Mg/Al LDHs has been used in the liquid phase oxidation of limonene [24], and on calcined Mg/Al LDHs for the one-pot synthesis of 4-methyl-2-pentanone (methyl isobutyl ketone) from acetone and hydrogen at atmospheric pressure [25]. In the latter case, the performance depends on the interplay between the acid-base and hydrogenation properties. More recently. 

Zaluski, L., Zaluska, A., Strom-Olsen, J.O. 1999. Hydrogenation properties of complex alkali metal hydrides fabricated by mechano-chemical synthesis. J Alloys Comp 290 71-78. 

T. Nabuki, M. Chiba, T. Kuji, Synthesis of CaMg-based bcc alloys and their hydrogenation properties, J. Alloys Compd. 446 47 (2007) 152-156. 

L. Guenee, V. Eavre-Nicolin, K. Yvon, Synthesis, crystal structure and hydrogenation properties of the ternary compounds LaNi Mg and NdNi Mg, J. Alloys Compd. 348 (2003) 129-137. 

A new illustration of this approach is given in this paper with the hydroprocessing of chloronitrobenzenes over the sulfided industrial hydro-treating catalysts, CoO-MoOj/y-Al 203 HR 306 and NiO-MoOj/y-AlHR 348 from Procatalyse. These catalysts have been shown to differ in their hydrogeno-lysis rather than in their hydrogenation properties (ref.2). 

Table 2-9. Hydrogen Properties Compared to Gasoline and Diesel Fuel...

Lanthanides as components in complex oxide systems In perovskites For conduction in electrocatalysis For oxidizing properties For hydrogenation properties For synthetic gas (CO-H2) reactions To provide sulfur oxides (SO, ) control In oxysulphides In other systems ... 

Table 2. Comparing hydrogen properties with other fuels. Based on LHV and 1 atm,...

Hydrogen Properties, College of the Desert, http //www.eere.energv.gov/hvdrogenand fuelcells/techvalidation/pdfs/fcmOlrO.pdf. December 2001. 

Both acidic and oxidation properties are obtained when Fe " is inserted in the zeolite lattice. The deposition of discrete metal particles (e.g., Pd, Pt) on the surface leads to bifunctional catalysts with both acidic and hydrogenation properties. These are frequently used to slow down the deposition of carbonaceous residues that eventually deactivate the catalyst by blocking the pores ( pore plugging ). 

Nevertheless, Tsushio et al. [34] reported the hydrogenation properties of MgNio.86Mlo.o3 (Ml = Cr, Fe, Co, Mn) alloys. Using the van t Hoff equation based on the desorption plateaus and the standard entropy of hydrogen gas 130.9 J mol they determined an enthalpy of hydride formation of the Cr-substituted alloy of —50kJ (mol H2), which is, for Mg-based alloys, a very high value. 

The effect of hydrogenating sites is only important when the exchange increases from 17 to 37-38 atoms. After that, the influence of Si sites prevails and hydrogenating properties decrease. 

Accordingly, for successive exchanges of sites, hydrogenating properties may come from a fraction of Sn sites. 

Furthermore, hydrogenating properties are detected for intermediate degrees of exchange. Some exchanged sites in the supercage can hydrogenate olefins. 

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