Ni-intAlx催化剂的化学合成及萘选择加氢性能

非（类）金属掺杂金属形成金属间隙或金属间化合物是一种设计高效、高选择性催化剂的重要手段.我们以萘基锂为强还原剂，NiCl₂与AlCl₃为原料，在室温下化学合成了Ni-^intAl_x纳米催化剂，并采用pXRD、N₂物理吸附、XPS、TEM、H₂-TPR、H₂-TPD等手段对催化剂进行表征.以萘选择加氢为探针反应，结果显示Ni-^intAl_x催化剂对萘选择加氢制四氢萘具有高活性及单一选择性.其中Ni-^intAl₁催化剂具有比Ni样品更纯的FCC晶型，比Ni-^intAl_1/3更适宜的铝掺杂量，及比Ni-^intAl₃更适宜的活性组分含量.镍铝之间的电子效应在一定程度上可调变中间产物四氢萘的吸附性能，避免过度加氢，在优化条件下萘转化率和四氢萘选择性分别达97%和98%，铝可用作第二金属掺杂以提高金属位点的活性和对中间产物的选择性.

Chemical Synthesis of Ni-intAlx Nanocatalysts for Selective Hydrogenation of Naphthalene

The formation of metal interstitial or intermetallic compounds by doping non (like)-metal into metals is an important means to design highly efficient and selective catalysts. Based on the metal reduction potential, Ni-^intAl_x nanocatalysts have been synthesized successfully at room temperature using lithium-naphthalenide as a strong reducing agent, anhydrous NiCl₂ and AlCl₃ as substrates, which have been used in the selective hydrogenation of unsaturated aromatic hydrocarbons. The as-prepared samples were characterized by pXRD, N₂ physisorption, XPS, TEM, H₂-TPR and H₂-TPD. The selective hydrogenation of naphthalene as a probe reaction showed that Ni-^intAl_x catalysts presented high activity and single selectivity for the selective hydrogenation of naphthalene to tetralin. The electronic effect between nickel and aluminium can adjust the adsorption performance of tetralin, the intermediate product, to avoid excessive hydrogenation. Among them, Ni-^intAl₁ catalyst had purer FCC crystalline phase of Ni and more suitable Al doping amount than other samples, showing high conversion of naphthalene (97%) and excellent selectivity to tetralin (98%). In addition, Ni-^intAl₁ catalyst presented high stability during 47 h with 3598 nmol/(g_Ni s) consumption rate of naphthalene and 99% selectivity to tetralin.