Study On Preparation Of Pyridine Graphdiyne Supported Metal Catalyst And Its Electrocatalytic Carbon Dioxide Reduction

With the rapid development of the global economy,the excessive use of fossil fuels has led to a serious energy crisis.In addition to the excessive release of carbon dioxide,which has also caused serious environmental problems.After the"dual carbon"goal was proposed,the capture and conversion of carbon dioxide has been more widely studied,among which electrochemical catalytic carbon dioxide reduction（CO₂RR）to generate more useful chemical products is considered to be an effective way of carbon resource recovery and sustainable fuel production.Metal catalysts play an important role in the field of electrochemical catalysis of CO₂RR.In the preparation of single atom catalyst,selecting the appropriate catalyst support is the key to the development of supported metal atomic catalyst.Graphdiyne is widely used as metal atomic catalyst support due to its excellent electrical conductivity,good electrochemical stability and large specific surface area.Based on the above background,this context was main research content which adopting the method of"bottom-up"design synthesis bpy GDY.And the performance of electrocatalytic CO₂ reduction was investigated by wet chemical loading of metal.The details are as follows:（1）Through the Sonogashira coupling reaction of hexaethynylbenzene（HEB）was coupled with 5,5’-dibromo-2,2’-pyridine,a pyridine-based graphdiyne（bpy GDY）carrier material was successfully synthesized on multi-walled carbon nanotubes（CNTs）.Transmission electron microscopy（TEM）showed that the synthesized bpy GDY material was uniformly coated on the multi-walled carbon nanotubes.（2）By chemical method,the catalytic active centers of metal Mn and Pd were directly introduced into the bpy GDY framework by using the limited domain effect of the cavity and the coordination of nitrogen-containing ligands.The bonding types and morphology were characterized by high resolution laser confocal microraman spectrometer,X-ray photoelectron spectroscopy（XPS）,transmission electron microscopy（TEM）,Fourier infrared（FT-IR）,X-ray diffraction（XRD）,etc.It is speculated that the coordination of manganese and palladium with bipyridine site and acetylene key point,respectively.（3）The composite materials were used as catalyst for electrocatalytic carbon dioxide reduction.The test results showed that Mn-CNTs-bpy GDY the Faraday efficiency of carbon monoxide could be maintained above 80%in the wide potential range of-1.0～-1.6V（vs.Ag/Ag Cl）,and the highest Faraday efficiency could reach93.9%.In addition,different catalyst loads have good carbon monoxide selectivity.In a certain range,different Mn loads have good carbon monoxide selectivity,and the increase of metal loads can improve the current density.Moreover,the synthesized Pd Mn-CNTs-bpy GDY bimetallic catalyst can well stabilize the ratio of syngas（CO/H₂≈1:1）,indicating that there is a synergistic catalytic effect between Pd and Mn metals.