Preparation And Performance Of Cathode And Anode Catalysts For Direct Liquid Fuel Cells

Direct liquid fuel cell?DLFC?is a kind of green energy with high conversion efficiency and has received more and more attention in recent years.Catalysts are an important part of DLFC.The development of catalysts with good performance and low cost is of great significance for the commercialization of DLFC.To this end,this paper carried out the following work:?1?In order to explore the influence of the interface on the activity and stability of the electrooxidation of formate and ethanol,Pd deposited on the Sn?OH?₂ surface by the reduction of Sn?OH?₂,and Ce O₂ deposited on the Sn?OH?₄ surface through the adsorption of Ce³⁺by OH,thus Sn O₂ surface could form Pd/Ce O₂ interfaces.The Pd/Ce O₂ interface was constructed and confirmed by energy dispersive X-ray spectroscopy?EDS?and X-ray photoelectron spectroscopy?XPS?.The electrochemical results show that Ce O₂ forms an interface with Pd and does not affect the electrochemically active area of Pd,indicating that poorly conductive metal oxides can also construct interfaces with precious metals by this method.The cyclic voltammetry and chronoamperometry were used to further compare the electrocatalytic behaviors of formate and ethanol at the Pd/Ce O₂ and Pd/Sn O₂interfaces.The results show that Pd/Ce O₂ is more active than Pd/Sn O₂.The reason may be that the Pd/Ce O₂ interface can inhibit the adsorption of CO poisoning products.?2?In order to further improve the activity of the Pd/Ce O₂ interface for formate electrooxidation,the chemical reaction between Ni?OH?₂ and Na₂Pd Cl₄ was first explored.The XRD characterization proved that the product was Pd O.Secondly,the chemical reaction between Ni?OH?₂ and Ce³⁺was explore too.The color of the Pd/Ni/CNTs and Pd/Ce O₂?Ni?/CNTs catalysts were prepared by the chemical reaction characterization showed that the addition of Ni increased the catalyst's electrooxidation activity on formate electrooxidation,while the addition of Ce O₂increased the activity of Ni,so that the activity and stability of the catalyst were improved overall.?3?In order to further develop the cathode catalyst for the direct liquid fuel cell,Ag-based catalystd were prepared using graphene?Gs?and N-doped graphene?GNs?as carriers.Gs and GNs were prepared by exfoliating graphite by electrochemical method.High power transmission electron microscopy?HRTEM?and Raman spectroscopy results indicate that Gs is a few layers of graphene,and infrared spectroscopy?IR?results indicate that the Gs has increased oxygen-containing groups.Ag/Gs and Ag/GNs catalysts were prepared by reducing Ag NO₃ with weak reducing agent HCOONa.Electrochemical tests found that both Gs and GNs are active in the oxygen reduction reaction?ORR?.Compared with Ag/Gs,Ag/GNs has a higher catalytic activity for ORR.