Characterisation of BN-supported palladium oxide catalyst used for hydrocarbon oxidation
Characterisation of BN-supported palladium oxide catalyst used for hydrocarbon oxidation
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DOI：
10.1016/j.apcata.2006.09.026
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发表时间：
2007-01
影响因子：
5.5
通讯作者：
G. Postole;B. Bonnetot;A. Gervasini;C. Guimon;A. Auroux;N. I. Ionescu;M. Cǎldǎraru
中科院分区：
文献类型：
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作者：
G. Postole;B. Bonnetot;A. Gervasini;C. Guimon;A. Auroux;N. I. Ionescu;M. Cǎldǎraru
六方氮化硼（BN）具有石墨型结构，表面积为184m2/g，用作氧化钯（PdO/BN）的载体。以硝酸钯为前驱体，通过初湿法在 BN 上沉积约 1wt% 的钯。通过BET、TEM、XRD、XPS、ICP、TG、TPD、原位交流电导率和氨吸附微量热法对载体和催化剂进行了表征。以丙烯和甲烷的氧化为模型反应，研究 PdO/BN 催化剂的催化性能。 BN 载体在高达 400°C 的丙烯氧化过程中几乎没有活性，而在 PdO/BN 上检测到氧化在 200°C 左右开始，这表明钯在吸附活性烃类物质中的作用。同时，该温度与 BN 和 PdO/BN 样品的电子电导率的增加一致，这对于氧作为亲电子物质的吸附/活化很重要。该催化剂在400℃以下的甲烷氧化中不活跃。在 400°C 时仅观察到约 2% 的 CH4 转化率，在 550°C 时急剧增加至 87%，其中甲烷仅转化为 CO2 和水。
Hexagonal boron nitride (BN), with a graphite-type structure and with surface area of 184m2/g was used as a support for palladium oxide (PdO/BN). About 1wt% of palladium was deposited on BN by incipient wetness method by using palladium nitrate as precursor. The support and the catalyst were characterized by BET, TEM, XRD, XPS, ICP, TG, TPD, in situ ac electrical conductivity and by ammonia adsorption microcalorimetry. Oxidation of propylene and methane were used as model reactions to study the catalytic properties of the PdO/BN catalyst. The BN support was practically inactive in propylene oxidation up to 400°C, while the onset of the oxidation was detected around 200°C on PdO/BN, which points out the role of the palladium in adsorption of the reactive hydrocarbon species. At the same time, this temperature is coincident with the increase of the electronic conductivity on both BN and PdO/BN samples, which is important for oxygen adsorption/activation as electrophilic species. The catalyst was inactive in methane oxidation below 400°C. Only about 2% CH4conversion was observed at 400°C, increasing sharply up to 87% at 550°C with methane transformation only to CO2and water.