非晶态镍硼/石墨烯复合材料的制备及其蒎烯催化加氢活性

以鳞片石墨为原料,采用Hummers法制得氧化石墨,经超声分散后制得稳定的氧化石墨烯(GO)分散液。以化学还原法一步制得非晶态Ni-B/rGO复合催化剂,并以蒎烯加氢为探针反应考察了催化剂的性能。结果表明,该催化剂对蒎烯加氢反应具有较高的催化活性,对生成顺式蒎烷具有较高对映选择性,达到96.5%以上,性能优于大多数传统的镍系催化剂甚至贵金属催化剂。该催化剂亦具有较好的稳定性,重复使用8次后,其转化率及对映选择性依然保持在较高水平。采用XRD、XPS、TEM等技术手段,研究了复合催化剂材料的结构与性质,初步探讨了非晶态Ni-B/rGO催化剂的构效关系。

Preparation of amorphous Ni-B/graphene composites for catalytic hydrogenation of pinene

Graphite oxide was prepared from flake graphite by Hummers method and dispersed by ultrasonic treatment. The amorphous Ni-B/rGO composite catalysts were prepared by one-step chemical reduction with NaBH₄ as reducing agent, and tested in the catalytic hydrogenation of pinene as the probing reaction. It shows that the as-prepared catalysts exhibit high catalytic activity and relatively high enantioselectivity of 96.5% for cis-pinane, which is better than the traditional Raney nickel and even noble metal catalysts. The catalyst possessed good stability, evidenced by that after 8-times testing cycles, both the conversion of pinene and the enantioselectivity to cis-pinane remained at a good level. The structure and properties of amorphous Ni-B/rGO composite catalysts were measured by XRD, XPS, TEM techniques, and the relationship between the catalytic performance and the structure was explored. The higher activity of the Ni-B/rGO amorphous catalyst could be attributed to the highly uniform dispersion of the Ni-B active species with unique electronic structure, and the interaction between Ni-B active species and the rGO in the composite catalysts．