Oxidation of $CH_4$ and $C_3H_8$ over combustion synthesized nanosize metal particles supported on $\alpha-Al_2O_3$

Bera, Parthasarathi and Patil, KC and Hegde, MS (2000) Oxidation of $CH_4$ and $C_3H_8$ over combustion synthesized nanosize metal particles supported on $\alpha-Al_2O_3$. In: Physical Chemistry Chemical Physics, 2 (3). pp. 373-378.

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Abstract

The catalytic oxidation of both $CH_4$ and $C_3H_8$ over combustion synthesized nanosize Pt, Pd, Ag and Au particles supported on $\alpha-Al_2O_3$ was investigated using the temperature programmed reaction technique in a packed bed tubular reactor. Complete $CH_4$ oxidation occurs over 1% $Pd/Al_2O_3$ and 1% $Pt/Al_2O_3$ at 350 and $425^o C$, respectively, whereas complete oxidation of $C_3H_8$ over 1% $Pt/Al_2O_3$ and 1% $Pd/Al_2O_3$ gives $CO_2$ and $H_2O$ at 175 and $300^o C$. Supported Ag and Au both show $CH_4$ and $C_3H_8$ conversion at much higher temperatures. The rate and turnover frequency (TOF) of $CH_4$ oxidation over 1% $Pd/Al_2O_3$ at $300^o C$ are $33.33 \mu mol g^{-1} s^{-1}$ and $0.34 s^{-1}$, respectively. Similarly, those of $C_3H_8$ oxidation over 1% $Pt/Al_2O_3$ at $150^o C$ are $116.67 \mu mol g^{-1} s^{-1}$ and $1.21 s^{-1}$, respectively. The $CH_4$ oxidation over supported Pt and Pd particles follows first order kinetics with respect to $CH_4$. The values of the rate constant (k) are 225 and $210 cm^3 g^{-1} s^{-1}$ over 1% $Pt/Al_2O_3$ and 1% $Pd/Al_2O_3$ at 300 and $400^o C$, respectively. Activation energy $(E_a)$ values are 95.5 and $128.4 kJ mol^{-1}$ for supported Pd and Pt, respectively.

Item Type:	Journal Article
Publication:	Physical Chemistry Chemical Physics
Publisher:	Royal Society of Chemistry
Additional Information:	Copyright of this article belongs to Royal Society of Chemistry.
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit Division of Chemical Sciences > Inorganic & Physical Chemistry
Date Deposited:	17 Oct 2008 06:44
Last Modified:	19 Sep 2010 04:50
URI:	http://eprints.iisc.ac.in/id/eprint/16067

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