The Design And Synthesis Of Carbon Supported Copper-silver Bimetallic Catalysts And Study On Their CO₂ Electroreduction Performance

Due to the fact that fossil fuels such as petroleum still dominate the supply of global energy,the carbon dioxide emission resulted from combustion is becoming increasingly serious.In addition,electricity generated by solar and wind energy is intermittent and can't be utilized on a large scale.In view of this,it is certainly meaningful to use such electricity to electrochemically convert CO₂ into fuels or high value-added chemicals under environmental conditions.However,CO₂ is quite stable under room temperature and atmospheric pressure.Thus it requires high active and selective catalysts to achieve efficient CO₂ electrocatalytic reduction.Precious monometallic catalysts cost relatively much while non-noble metal catalysts possess larger overpotential for CO₂ electroreduction,and the selectivity of single product is relatively poor with the stability of catalysts being unsatisfying.All of these facts limit its massive application.It is an effective strategy to improve electrocatalytic performance of metals by designing appropriate?supported?bimetallic catalysts.In this paper,ultrasonication assisted wet chemical method was adopted to prepare Cu-Ag bimetals and carbon black supported Cu-Ag bimetallic catalysts.Means?or instruments?such as electron microscopy,X-ray diffraction,X-ray photoelectron spectroscopy,electrochemical workstation,gas chromatography etc.,were used for characterization of the structure as well as catalytic performance tests of as-prepared catalysts.Cu-Ag bimetallic catalysts with specific mole ratio can effectively break the "dilution effect" on products selectivity between single metal?copper and silver?.Compared with pure Cu or Ag catalyst,Cu-Ag bimetals with specific composition can improve the selectivity of ethylene and carbon monoxide respectively.While the catalytic activity and selectivity of carbon black supported Cu-Ag bimetals with different surface composition show obvious dependence on surface composition.This work provides an useful reference for the tailoring of activity and selectivity of bimetallic catalysts for CO₂ electroreduction by regulating the overall composition of bimetals and their surface elemental configuration.