Study On Application Of Self-n-poped Fullerene Ammonium Iodide In Electrocatalysis

Fullerenes and their derivatives have shown wide applications in the fields such as photoelectricity and biomedicine for their unique spherical ?-electronic structure as well as superior physicochemical properties.Because of their characteristic molecular and supramolecular self-assembled structure,the potential value of self-n-doped fullerene ammonium iodides has been proven in the application of the fuel cell anode catalyst support.Herein,based on previous work of the structure-activity relationship of the fullerene ammonium and its behavior as fuel cell anode catalyst support we conduct the following two studies on the application of self-n-doped fullerene ammonium in electrocatalyst support for the purpose of enhancing the catalyst activity and stability.1.Solvent engineering to adjust the morphology of self-n-doped fullerene ammonium iodides(PCBANI)electrocatalyst support.So far the application of PCBANI in electrocatalysis support has been limited by the insufficiency of fullerene's specific surface area and pore space framework.In this work,we found solvent engineering of pristine PCBANI aggregate could maintain stacked short-range assembly structure and porous morphology.Moreover,PCBANI film fabricated from the optimized DMSO/methanol could immobilize Pd NPs with a uniform size of around 4.8 ± 1.7 nm which was characterized by scanning electron microscopy(SEM),transmission electron microscopy(TEM),and selected area electron diffraction(SAED).The resulting Pd/PCBANI-1 coated electrode exhibits a mass-specific activity for Pd of 1786.3 mA mg-1 at a scan rate of 50 mV s-1 and good stability toward alcohol electrooxidation,which are both significantly higher than that of the Pd/PCBANI-2 fabricated from PCBANI's acetic acid/methanol dispersion and commercial Pd/C(active carbon).The high performance of the as-fabricated catalyst is attributed to highly conductive and porous PCBANI support,good dispersibility of Pd NPs on support,and favorable mass transfer.2.Research on graphene-fullerene electrocatalyst composite support.Graphene is widely used as a kind of electrocatalyst support material due to its superior electrical conductivity and chemical stability.Generally,graphene is prepared from the reduction of oxidized graphite(GO).However,the strong ?-? interaction between layers could result in graphene stacking,which influences the performance of the supported catalyst.In this work,graphene layer stacking in the reduced GO(RGO)could be prevented by inserting PCBANI with high electrical conductivity into GO layers through hydrogen-bonding,electrostatic and ?-? stacking interaction.Hydrazine hydrate hydrothermal-reduction method was adopted to produce the hybrid composite(RGO-PCBANI)with different ratios of RGO to PCBANI.Then,these materials were used to support Pd nanoparticle to fabricate Pd/RGO-PCBANI electrocatalysts on the electrode.The morphology and structure of the RGO-PCBANI and Pd/RGO-PCBANI were characterized by SEM,TEM,X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS).Furthermore,the electrocatalytic performance of Pd/RGO-PCBANI towards the ethanol oxidation was evaluated by using electrochemical methods such as cyclic voltammetry and chronoamperometry.The results showed that the prepared RGO-PCBANI(6:1)support displayed good dispersibility and could immobilize Pd nanoparticle with 5.2 ± 3.2 nm average size.Moreover,the fabricated Pd/RGO-PCBANI(6:1)catalyst exhibited the best catalyst activity and stability.The mass current density reached 1288.8 mA mg-1,which is much better than that of Pd/RGO and Pd/C.The good performance of Pd/RGO-PCBANI in the catalytic electro-oxidation of ethanol was attributed to highly conductive PCBANI's spacer function in the RGO-PCBANI composite support.This paper laid a solid foundation for further study of fullerene ammonium salts in electrocatalysis.