Hydrogen production from ethanol on Rh/MgO based catalysts: The influence of rhodium precursor on catalytic performance
- 作者：N. Palmeri ; S. Cavallaro ; V. Chiodo ; S. Freni ; F. Frusteri ; J.C.J. Bart
- 关键词：Rhodium ; Rh/MgO ; Ethanol ; Steam reforming ; Hydrogen production
- 刊名：International Journal of Hydrogen Energy
- 出版年：2007
- 期刊代码：42_03603199
- 类别：ch
- 出版时间：October 2007
- 卷：32
- 期：15
- 页码：3335-3342
- 文件大小：259 K
摘要
The influence of the metal precursor on the catalytic behaviour of Rh/MgO catalysts in steam reforming of ethanol was investigated. Rhodium nitrate and acetylacetonate, having different chemical properties, have been used as hydrophilic and hydrophobic precursors, respectively. More highly dispersed catalysts were obtained using Rh-nitrate, while catalysts prepared with Rh-acetylacetonate show higher stability being generally less affected by coke formation. Catalytic tests performed at molten carbonate fuel cell (MCFC) operative conditions ve&_udi=B6V3F-4NXGS7Y-6&_mathId=mml84&_user=10&_cdi=5729&_rdoc=34&_acct=C000050221&_version=1&_userid=10&md5=e8cd3785462cc228fae5498e1bad6a07">
view the MathML source" align="absbottom" border="0" height=15 width=95> clearly show a structure-sensitive reaction since the turnover frequency (TOF) significantly increases with the mean Rh particle size. Thermodynamic considerations on the basis of the outlet composition allowed to calculate the experimental equilibrium constant ve&_udi=B6V3F-4NXGS7Y-6&_mathId=mml85&_user=10&_cdi=5729&_rdoc=34&_acct=C000050221&_version=1&_userid=10&md5=17bb87642812e4aad52d095a0765e64a" title="Click to view the MathML source">(Kexp) for (i) methane steam reforming (MSR), (ii) water–gas shift (WGS), (iii) methane pyrolysis and (iv) Boudouard reactions. By comparing ve&_udi=B6V3F-4NXGS7Y-6&_mathId=mml86&_user=10&_cdi=5729&_rdoc=34&_acct=C000050221&_version=1&_userid=10&md5=e14b20e97a20366c9a2f30b7470a51d5" title="Click to view the MathML source">Kexp with the equilibrium provided mass action ratios ve&_udi=B6V3F-4NXGS7Y-6&_mathId=mml87&_user=10&_cdi=5729&_rdoc=34&_acct=C000050221&_version=1&_userid=10&md5=4933eb336a9344dd93417fa70fbb7860" title="Click to view the MathML source">(Keq), we suggest that only WGS is fully equilibrated and that coke is formed mainly through methane pyrolysis.