Pd-Cu Nano Bimetallic Catalyst Pyridine Direct Coupling Synthsis Of 2,2'-Pyridine Research

2,2'-Bipyridine (2,2-Bipyriding) is not only an important intermediate in modern organic synthesis, but also widely used in medicine, pesticide, paint, temperature coating and other fields. In industrial production, the demand of 2'-bipyridine is also increasing. In this paper, 2,2'-bipyridine was synthesized by direct coupling of pyridine with supported bimetallic nanocatalyst.In this paper , the author explored the carrier of the catalyst, the active components,the best reaction conditions and carried characterization analysis by using X-ray diffraction ( XRD ), X-ray photoelectron spectroscopy ( XPS ), scanning electron microscopy ( SEM ),transmission electron microscopy ( TEM ) and BET and other detection means. The active components Pd and Cu were then supported on the support?-Al2O3 by impregnation. The experimental results show that Pd-Cu / Al2O3 is superior to Pd- / Al2O3, a traditional nano-catalyst. During the preparation of the catalyst, the addition of metal Cu reduced the amount of Pd used in the noble metal and reduced the cost of the catalyst. The results show that the addition of metal Cu is beneficial to the reduction of metal Pd, the introduction of metal Pd, the growth of Cu crystal is inhibited,and the agglomeration of catalyst is avoided. Metal Pd and metal Cu form a valence state between the elemental and the oxide Pd-Cu alloy supported on the carrier. The formation of bimetallic alloy, the catalyst showed more excellent catalytic activity and stability, and determined the active ingredient particles were spherical, the size of about 5 nm.After a great deal of experiments, the optimum conditions for the synthesis of 2,2'-bipyridine by Pd-Cu / Al2O3-catalyzed direct coupling of pyridine were: The molar ratio of Pd to Cu in Pd-Cu / Al2O3 catalyst is 1:2, N2 pressure is of 1 MPa, a reaction temperature is of 310 ?, the amount of catalyst is 3.0 wt % (total raw material mass),the reaction time is 16 h, the conversion of pyridine was 35.4 %, the selectivity of 2,2'-Bipyridine is up to 99%.