The Anti-poisoning Ability Research Of Pd/Pt-based Catalysts In Fuel Cells

As an ideal new energy technology,fuel cells have broad application prospects so it has been a hot topic in basic research and market.Palladium?Pd?and platinum?Pt?based nanocatalysts have been a hot topic in the field of catalysis,especially in the anode and cathode reaction of fuel cells,due to their unique physical and chemical properties.However,fuel cells usually use small organic molecules?methanol,ethanol,etc.?as a continuous source of fuel,but these alcohols are difficult to produce carbon dioxide?CO₂?and water?H₂O?totally in the process of electrocatalytic oxidation.In the catalytic process,some intermediate products such as carbon monoxide-like species?CO-like species?are difficult to avoid.This phenmonen will cause serious "catalyst poisoning" in the catalytic process due to the strong chemical adsorption between Pd and Pt precious metals and CO,leading to the poor activity and stability of the catalysts.This not only reduces the actual catalytic efficiency of fuel cells,but also indirectly improves the the cost of fuel cells in practical application.It is a major factor that hinders the large-scale commercial application of fuel cells.Therefore,it is of great practical significance to develop a catalyst with high catalytic activity as well as excellent anti-poisoning ability for cathode and anode reactions of fuel cells.In recent years,although some research achievements have been made in improving the anti-poisoning ability of the noble metal catalysts,it is still a great challenge to achieve the high catalytic activity and excellent anti-poisoning ability of the noble metal catalysts simultaneously.In this paper,Pt_xPb networked nanowires?NNWs?,PtBi nanosheeets?NSs?and Pd@NiO nanoparticles?NPs?were synthesized by effectively controlled their morphology,composition and surface structure.The relationship among structure characteristics,growth mechanism and catalytic performance have been studied in depth.The main contents are summarized as follows:Chapter 1.The background of catalyst poisoning in fuel cells with its causes,mechanism and research progress.Chapter 2.A method for the preparation of Pt_xPb NNWs was proposed.The reaction temperature is the key to regulate the components of Pt_xPb NNWs.Pt_xPb NNWs exhibit high catalytic activity and excellent anti-poisoning ability in the ethylene glycol electrooxidation reaction?ethylene glycol oelectroxidation reaction,EGOR?due to the introduction of Pb,and the Pt_xPb NNWs surface is rich in defects and atomic step surface.Chapter 3.A method for the preparation of PtBi NSs is proposed.Compared with PtBi NPs and commercial Pt/C,PtBi NSs exhibit high catalytic activity and excellent anti-poisoning ability in ORR testing because PtBi NSs has unique ordered intermetallic compound structure as well as the advantage of two dimensional?2D?structure nanomaterials.Chapter 4.A method of preparing Pd@NiO NPs with unique core-shell structure was proposed.A series of Pd@NiO-x/C were obtained through H₂O₂ treatment over Pd@Ni/C.The fine regulation of core shell interface structure can be achieved by optimizing the oxidation degree of the Ni shell.The optimized Pd@NiO-0.3/C exhibit high ORR catalytic activity and excellent anti-poisoning due to the surface modification and protection of the NiO shell.