Synthesie And Performances Investigation Of Pd-Based Anode Electrocatalysts For Alkaline Direct Alcohols Fuel Cell

Direct alcohol fuel cell(DAFC)has become a research hotspot due to the advantages of high energy conversion efficiency,green,rich source of fuel,storage and transportation is convenient etc.The development of the anode catalyst is the key to DAFC.But the commercialization of DAFC is limited by its defects such as high cost low activity and so on.In order to improve the activity and stability of Pd catalysts in alkaline medium,long chain polymers are introduced into the Pd based catalyst,with the introduction of Phosphomolybdic acid and other metals to improve the activity and stability of the catalysts via the spatial structure change and the interaction;Microwave assisted glycol reduction method is employed,when preparing a polymer-modified GNPs-CNTs Pd-based catalyst.Transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS)were used to characterize the morphology,composition and structure of catalysts.The electrochemical methods as Cyclic voltammetry(CV),Linear sweep voltammetry(LSV),Electrochemical impedance spectroscopy(EIS)and Chronoamperometry(CA)were applied to characterize the Pd particles,studying the catalytic activity and stability in the alcohol oxidation reaction.The main research results are as follows:(1)Pd/CNTs catalysts were modified by the conducting polymer(polypyrrole and polyaniline).The results show that the presence of polymer,and the catalytic activity was promoted.Pd/CNTs catalyst functionalized by polyaniline combined with Chit has better alcohol oxidation activity and stability than Pd/CNTs-PANI ?Pd/CNTs-PPy catalyst.(2)Pd/CNTs-HPMo catalyst with the mass ratio of CNTs to HPMo of 1:0.02 has the best performance for alcohol oxidation.TEM and the electrochemical results show that the combination of Phosphomolybdic acid with Chit can improve the microstructure and dynamic performance.(3)For PdM binary catalysts,PdAg/CNTs-Chit,PdAu/CNTs-PANI catalysts modified with Chit and PANIshowed better activity and stronger electrochemical stability.Ag,Au particles can improve the Pd/CNTs catalyst electric catalytic properties of alcohol.Ag,Au and Pd particles are showed double functional effect.(4)Mixed carrier CNTs-GNPs were modified by the conducting polymer polypyrrole and PDDA can improve the physical mixture of instability.The characterization results show that the average particle size decreases with the increase of Pd particle loading on the carrier.Compared with Pd/CNTs-GNPs catalyst,it shows higher catalytic performances for alcohol oxidation.