Low-Temperature (553 K) Catalytic Growth of Highly Ordered Carbon Filaments during Hydrodechlorination Reactions
Low-Temperature (553 K) Catalytic Growth of Highly Ordered Carbon Filaments during Hydrodechlorination Reactions
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DOI：
10.1021/jp000048z
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发表时间：
2000-04
影响因子：
3.3
通讯作者：
C. Menini;Colin W. Park;and Rik Brydson;M. Keane
中科院分区：
文献类型：
--
作者：
C. Menini;Colin W. Park;and Rik Brydson;M. Keane
在Ni/SiO2催化剂上氯苯气相加氢脱氯制苯反应中，用HCl或HBr气体对催化剂进行预处理，可诱导催化剂表面高度有序的碳纤维生长。观察到这种丝状生长发生在553 K，即，比先前文献中报道的用于石墨碳的催化形成的温度低至少150 K。卤化氢预处理也导致在一个明显的平均镍颗粒尺寸的增加和加氢脱氯活性的抑制。在不存在这种预处理的情况下，催化剂表现出稳定的加氢脱氯活性，并且没有任何丝状碳生长的证据。对经卤化物处理的样品的分析显示，钾的存在在新鲜活化的催化剂中并不明显，而是由于卤化氢气体对微型反应器单元的腐蚀性攻击而引入的。我们的低温有序碳生长的来源必须是电子在氮原子。
In the gas-phase hydrodechlorination of chlorobenzene to benzene over Ni/SiO2, a pretreatment of the catalyst with HCl or HBr gas induced the growth of highly ordered carbon filaments from the catalyst surface. This filamentous growth was observed to occur at 553 K, i.e., at least 150 K less than that reported previously in the literature for the catalytic formation of graphitic carbon. The hydrogen halide pretreatment also resulted in an appreciable increase in the average nickel particle size and a suppression of hydrodechlorination activity. In the absence of this pretreatment the catalyst exhibited stable hydrodechlorination activity and there was no evidence of any filamentous carbon growth. Analysis of the halide-treated samples revealed the presence of potassium that was not evident in the freshly activated catalyst but was introduced as a result of a corrosive attack of the hydrogen halide gas on the microreactor unit. The source of our low-temperature ordered carbon growth must be electronic in n...