Total oxidation of methane over Pd catalysts supported on silicon nitride - Influence of support nature
Total oxidation of methane over Pd catalysts supported on silicon nitride - Influence of support nature
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DOI：
10.1016/j.cej.2004.12.009
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发表时间：
2005-03-15
影响因子：
15.1
通讯作者：
Bertolini, JC
中科院分区：
文献类型：
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作者：
Kurzina, I;Aires, FJCS;Bertolini, JC
具有高热稳定性和导热性的非氧化物耐火材料如氮化硅可用作催化载体。选择具有不同比面积和结晶度的氮化硅：非晶氮化硅（SiN-am）、氮气流下1450℃（120分钟）退火的非晶氮化硅（SiN-annl）和α-Si3N4作为Pd催化剂的载体。商业非晶氮化硅含有少量的结晶相，α/β Si3N4 比率为2.3。非晶氮化硅的退火导致相组成以及粉末形态的变化。退火后，α/β Si3N4 比为 6.6，晶相数量增加了 80%。通过在氮化硅粉末的甲苯溶液中浸渍乙酰丙酮钯(II)来制备钯催化剂，并在甲烷全氧化反应中进行测试。研究发现载体的相组成和晶态对 Pd 催化剂的催化性能有很大影响。沉积在非晶Si3N4上的Pd催化剂的活性很差。它随着载体的α-Si3N4含量而增加。 (c) 2004 Elsevier B.V. 保留所有权利。
Non-oxide refractory materials such as silicon nitride showing high thermal stability and thermal conductivity can be used as catalytic supports. Silicon nitride with different specific area and crystallinity: amorphous silicon nitride (SiN-am), amorphous silicon nitride annealed at 1450 degrees C (120min) under nitrogen flow (SiN-annl) and alpha-Si3N4 were chosen as supports for Pd catalysts. Commercial amorphous silicon nitride contains a small amount of crystalline phase with alpha/beta Si3N4 ratio of 2.3. Annealing of the amorphous silicon nitride leads to changes in the phase composition, as well as in the morphology of the powder. An increase of the amount of crystalline phases up to 80% with alpha/beta Si3N4 ratio of 6.6 was obtained after annealing. Palladium catalysts were prepared by impregnation of Pd(II) acetylacetonate in toluene solution of silicon nitride powder and were tested in the methane total oxidation reaction. A strong influence of the phase composition and the crystalline state of supports on the catalytic properties of Pd catalysts was found. The activity of Pd catalysts deposited on the amorphous Si3N4 is very poor. It increases with the alpha-Si3N4 content of the support. (c) 2004 Elsevier B.V. All rights reserved.