Pt Nanoparticles Supports On Titanium Nitride Nanotubes Derived From MOF And Heteroatom Catalysts For Methanol Oxidation

Although direct methanol fuel cells（DMFCs）are under booming development,they are still faced with sluggish situations,including rare resources of precious metal,low catalytic activity due to easily poison of Pt by carbon monoxide,etc.Commercial Pt/C catalysts are easily trend to corrosion due to weak physical adsorption between Pt and C during long-term experiments,and Pt particles are trend to agglomerate and cause deactivation.To speed up the commercialization of DMFCs,researchers are devoted to synthesis effective and robust catalysts leading to a scope of advanced works.In this paper,a novel Pt-Ce O₂/Ti N nanotube（Ti N NTs）catalyst derived from Ce-metal organic framework and boron-nitrogen-carbon co-doped nanotubes（BNC NTs）used as Pt-supported carriers were prepared for the first time.Scanning electron microscope（SEM）,transmission electron microscope（TEM）,X-ray diffraction（XRD）,nitrogen adsorption/desorption specific surface area test（BET）,Raman test,and electrochemical test were performed to characterize the support and catalyst.The electrochemical test confirmed the catalyst Pt-Ce O₂/Ti N NTs had better methanol electrocatalytic performance,higher resistance to CO poisoning and stability.XRD showed that Ce O₂/Ti N NTs were successfully prepared with Ce-MOF as the precursor.SEM and TEM confirmed that the carrier was a hollow porous structure,and the surface of the tube wall was a combination of nano-sheet structures.At the same time,it could be observed that the surface of Ce O₂/Ti N NTs were a porous structure composed of tightly combined nanocrystalline phases.BET indicated that Ce O₂/Ti N NTs had a mesoporous structure and a large specific surface area.CV test showed that Ce O₂/Ti N NTs had excellent electrochemical stability.CA test showed that Pt-Ce O₂/Ti N NTs had better corrosion resistance and stability.The MOR test showed that Pt-Ce O₂/Ti N NTs exhibited better methanol electrocatalytic activity.XPS further showed that Ce O₂derived from Ce-MOF could provide electrons to Pt,thereby increasing the content of Pt（0）which was favorable for the oxidation of methanol,and Ce O₂was beneficial to reduce the d-band vacancy of Pt and Fermi level.Therefore,the interaction between Pt and the intermediate product CO was weakened,resulting Pt-Ce O₂/Ti N NTs had better electrocatalytic performance for methanol.The electrochemical test confirmed Pt/BNC NTs had better methanol electrocatalytic performance,higher resistance to CO poisoning and stability.Elemental Mapping analysis and XRD analysis showed that the carrier BNC NTs were successfully synthesized.The SEM and TEM proved that the as-prepared carrier BNC NTs had a tubular structure.The Raman test proved that the ratio of the D peak intensity I_Dand G peak intensity I_G（I_D/I_G）of BNC NTs was 1.08,which verified the tubular morphology of BNC NTs.Moreover,the I_D/I_Gratio showed that the doped of B brought many defect sites,which provided more active sites for the loading of Pt nanoparticles（NPs）.MOR test showed that Pt/BNC NTs had the best electrocatalytic ability for MOR.The chronoamperometry test showed that Pt/BNC NTs had better anti-poisoning ability and stability.The ADT test results of Pt/BNC NTs further proved its stability.XPS showed that the electronic interaction between Pt and B could improve the electrocatalytic performance and morphology of Pt.Moreover,due to the doping of B,the center of the d band of Pt moves down,and the strong electronic effect between Pt and B could enhance electrocatalytic activity for MOR.