Preparation And Properties Of Direct Formate Fuel Cell Anode Catalysts

Direct formate fuel cells（DFFCs）has gained lots of attention in recent years due to its various advantages,such as non-toxic,non-corrosive and good oxidation.Currently,DFFCs anode catalyst mainly use noble metal-based ones,such as platinum and palladium,which is of high cost,low abundance and short service life that constricted the commercialization process of DFFCs.So,reducing the usage of noble metals and developing high-activity,high-stability,low platinum（or palladium）loading catalyst is necessary for the commercialization of DFFCs.This paper has carried out with the following several aspects:（1）To improve the utilization of noble metal catalysts,Pd deposition on Au nanoparticles supported by carbon nanotubes（CNTs）through galvanic replacement reaction was explored to prepare Pd/Au/CNTs catalysts,which shows superior mass specific activity of Pd moieties for formate oxidation.By further introducing CeO₂on Au surface and then depositing Pd,Pd/CeO₂/Au/CNTs catalysts were prepared and with improved anti-poisoning performances compared with Pd/Au/CNTs.This is because of the formation of Pd/CeO₂ interfaces,which is efficient for lowering CO stripping potential.（2）Considering the influence of the metal particle size to the catalytic performance of different catalysts,Pd-SnO₂/CeO₂/CNTs and Au-SnO₂/CeO₂/CNTs with more smaller metal particle size were prepared in advance.Similarly,Pd-Au-SnO₂/Ce O₂/CNTs with high Pd utilization was prepared by deposition Pd on Au-SnO₂/CeO₂/CNTs through galvanic replacement reaction.Compared those two different Pd-catalysts as anode catalysts for formate oxidation and contrast with Pd/C,the result shows that Pd-SnO₂/CeO₂/CNTs and Pd/C reveals the approximate mass specific activity for formate electrooxidation during long time i-t measurement,which are all inferior to Pd-Au-SnO₂/CeO₂/CNTs.And we also compared the performance differences between the two catalysts with different sizes,the result shows that particle size of Au has an effect on catalytic activity of the catalyst indeed,but have a little effect in anti-poison performance.（3）On the basis of the first two researching about the anode catalyst for formate oxidation,using Pd-gold foil paper compared by UPD and silverex foam deposited with Pd as anode catalyst,respectively.Pd/C as cathode catalyst and polyethylene（PE）anion-exchange membrane to fabricate a DFFC system and test the battery performance which shows lower open circuit potentials（OCP）and poor battery performance.Further optimizing relevant conditions and improve the performance of the DFFC system.