Pd_xAg_y(m)/RGO Synthesis And Catalysis In Electrooxidation Oxidation Reactions Of Alcohols

Graphene is a new type of carbon material.It has unique physical and chemical properties,such as ultra-high electrical conductivity,large specific surface area,and excellent thermal stability.It is widely used in various scientific fields.The graphene-based composite materials mainly include composites with metals and their oxides,composites with polymers,etc.Among them,due to the high specific strength,high specific modulus,high corrosion resistance,excellent electrothermal performance and excellent processing performance of metal materials,Metal nanoparticles（NPs）/graphene composite materials have been extensively studied.It was found that the metal nanoparticles（NPs）/graphene composite material not only maintains the excellent performance of graphene,but also can take advantage of the synergistic effect between the two,showing superior performance than graphene and metal nanomaterials alone.The application of fuel cells,supercapacitors and flexible conductive films has broad prospects.As a new type of clean energy equipment,fuel cell has great application potential in solving energy crisis and environmental pollution.In this work,co-reduction method was used to load palladium（Pd）silver（Ag）alloy nanoparticles（NPs）on reduced graphene（RGO）nanosheets to obtain a series of Pd_xAg_y（m）/RGO composite materials,and then they were analyzed by a series of characterization methods,and then used as a catalyst for methanol electrooxidation（MOR）,ethanol electrooxidation（EOR）,ethylene glycol electrooxidation（EGOR）,and glycerol electrooxidation（GOR）.The results showed excellent catalytic performance.The main research contents of this work are as follows:（1）Using co-reduction method,using ethylene glycol（EG）as the reducing agent,GO and K₂Pd Cl₄and Ag NO₃are reduced to produce Pd_xAg_y（m）/RGO composite material.In the absence of other reducing agents and stabilizers,by adjusting the ratio of metal precursors to GO,materials of different Pd Ag alloys were successfully grown on RGO.Then fourier transform infrared Raman spectroscopy and X-ray diffraction analysis,X-ray photoelectron spectroscopy,transmission electron microscopy and other characterization methods were used to analyze the properties of the composite material.It was found that the Pd Ag NPs were evenly distributed on the surface of the RGO.The overall structure was in line with the theoretical design,and the diameter of the nanoparticles in the composite material will increase through the increase of the number of metal precursors.（2）Inspired by the rapid development of fuel cells,these composite materials were further tested for their catalytic performance against MOR,EOR,EGOR,and GOR in alkaline media.The catalytic performance of the catalyst was evaluated by cyclic voltammetry（CV）and electrochemical impedance spectroscopy（EIS）,and the catalytic performance of the Pd_xAg_y（m）/RGO composite material synthesized in this experiment was found to be excellent,including Pd_0.45Ag_0.55（3.6）/RGO,Pd_0.15Ag_0.85（2.4）/RGO and Pd_0.05Ag_0.95（1.2）/RGO showed the highest electrochemical density in EOR,EGOR and GOR,respectively48.8 A cm^-2mg^-1,141.3 A cm^-2mg^-1and 136.5 A cm^-2mg^-1,so it can be used as a promising anode catalyst for ethanol fuel cells（DEFCs）,ethylene glycol fuel cells（DEGFCs）and glycerin fuel cells（DGFCs）.（3）In addition,this work also starts from the inherent electronic properties and lattice structure of the material itself,and further explores the factors that affect the catalytic oxidation of alcohols,and establishes the relationship between the composite material structure and the catalytic performance of different alcohols.This research method can provide new ideas for designing a catalyst with excellent efficiency for the electrooxidation of alcohols,so as to better understand its catalytic mechanism.