Methane ignition catalyzed by in situ generated palladium nanoparticles
Methane ignition catalyzed by in situ generated palladium nanoparticles
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DOI：
10.1016/j.combustflame.2009.07.012
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发表时间：
2010-03
影响因子：
4.4
通讯作者：
T. Shimizu;A. Abid;G. Poskrebyshev;Hai Wang;J. Nabity;J. R. Engel;J. Yu;D. Wickham;B. Devener;S. Anderson;Skip Williams
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文献类型：
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作者：
T. Shimizu;A. Abid;G. Poskrebyshev;Hai Wang;J. Nabity;J. R. Engel;J. Yu;D. Wickham;B. Devener;S. Anderson;Skip Williams
Catalytic ignition of methane over the surfaces of freely-suspended and in situ generated palladium nanoparticles was investigated experimentally and numerically. The experiments were conducted in a laminar flow reactor. The palladium precursor was a compound (Pd(THD)2, THD: 2,2,6,6-tetramethyl-3,5-heptanedione) dissolved in toluene and injected into the flow reactor as a fine aerosol, along with a methane–oxygen–nitrogen mixture. For experimental conditions chosen in this study, non-catalytic, homogeneous ignition was observed at a furnace temperature of ∼1123K, whereas ignition of the same mixture with the precursor was found to be ∼973K. In situ production of Pd/PdO nanoparticles was confirmed by scanning mobility, transmission electron microscopy and X-ray photoelectron spectroscopy analyses of particles collected at the reactor exit. The catalyst particle size distribution was log-normal. Depending on the precursor loading, the median diameter ranged from 10 to 30nm. The mechanism behind catalytic ignition was examined using a combined gas-phase and gas-surface reaction model. Simulation results match the experiments closely and suggest that palladium nanocatalyst significantly shortens the ignition delay times of methane–air mixtures over a wide range of conditions.
