磁性花生壳负载钯催化剂的制备及催化氨硼烷释氢性能

以高锰酸钾改性后的花生壳为原料,通过共沉淀法制备了磁性花生壳(PSK-Fe_3O_4)复合材料,并以其为载体制备了磁性花生壳负载钯催化剂(Pd/PSK-Fe_3O_4).以XRD、FT-IR、TEM、XPS、TG等表征手段对该催化剂进行了表征,并将其应用于催化氨硼烷水解释氢.结果表明:Pd/PSK-Fe_3O_4催化剂在催化氨硼烷水解反应中表现出较好的催化活性,其转换频率(TOF)为6.7 mol_(H2)·mol_(Pd)~(-1)·min~(-1),表观活化能(E_(app))为28.0 kJ mol~(-1).Pd/PSK-Fe_3O_4催化氨硼烷水解释氢反应对于催化剂浓度和氨硼烷浓度的反应级数分别为一级和零级.此外,循环实验表明该催化剂具有较好的循环稳定性.

Preparation and Catalytic Performance of Magnetic Peanut Shell Supported Palladium Catalyst for the Hydrolytic Dehydrogenation of Ammonia Borane

A magentic peanut shell( PSK-Fe_3O_4) composite is prepared from peanut shell modified with KMnO_4 by a co-precipitation method. Then,the composite is employed as supports to anchor palladium by a chemical reduction method. The samples are characterized by XRD、FT-IR、TEM、XPS and TG.The catalytic performance in the hydrolytic dehydrogenation of ammonia borane( NH_3BH_3,AB) is investigated in details. The results show that Pd/PSK-Fe_3O_4 catalyst exhibits good catalytic activity and the corresponding turnover frequency( TOF) reaches up to 6.7 mol_(H2)·mol_(Pd)~(-1)·min~(-1) and the apparent activation energy(E_(app)) of the reaction is as low as28.0 kJ mol~(-1). The corresponding reaction order of the catalyst and AB concentrations are first order and zero order in the hydrolytic dehydrogenation of AB,respectively. In addition,the catalyst has a satisfactory reusability.