Synthesis And Electrochemical Catalysis Activity Study Of Pt-based Alloy Materials

Nano materials because of its have unique physical properties and chemical properties, has been praised by the attention of scientists. So far, the research on nanometer material has a lot of achievements, nanomaterials have been widely applied to the optical sensors, bionics, catalytic and medicinal chemistry, and other fields. As in recent years fuel cell research has become more and more popular, the catalyst as the key factors influencing the fuel cell performance and large scale application has become one of the focus of attention. Precious metals platinum is selected as the reaction catalyst materials, because of its high catalytic activity. But precious metal platinum catalyst also has obvious disadvantages, the expensive cost and carbon poisoning occur easily. In this paper, based on the template method we successfully obtain nano Pt-Ru alloy catalyst, nano Pt-Ni alloy catalyst and Pt-Ru alloy nanowires catalyst three kinds of material. After the performance test for three different kinds of materials we find that, compared with the current commercial Pt black catalyst used, the materials we hace prepared have higher catalytic activity, better anti poisoning ability for carbon and lower cost. The main work is as follows:Through the use of surfactant P123 as soft template, ascorbic acid (AA) are prepared by the reduction of nano Pt-Ru alloy catalyst. Through the study of electrochemical experiments found that, due to the accumulation of a catalyst particle size of spherical structure with mesoporous structure on the surface of 3nmand the catalyst has higher electrochemical catalytic activity surface area (ECSA) compared to commercial Pt black catalyst. At the same time, due to the introduction of metal Ru and Pt formed alloy structure, thereby increasing the ability of anti carbon catalyst poisoning, and because of the low price of Ru, the catalyst material cost relative to commercial Pt black catalyst composed of pure platinum is decreased.By using nonionic surfactant Brij58 as soft template, reduction in ice bath using sodium borohydride, successfully prepared the nano Pt-Ni alloy catalysts containing different mass fraction of Pt. Alloy catalyst prepared by particle size in the range of 6-8nm,. Through the study of electrochemical experiments showed that the electrochemical catalytic activity area of six different concentrations are significantly higher than that of commercial Pt black catalyst, at the same time, due to the ability to introduce metal catalyst Ni has anti carbon poisoning has been enhanced, and because Ni low price, greatly reduces the cost of the catalyst. At the same time, by comparing the six kinds of different content of catalyst material properties of Pt wt%=50% samples with the highest electrochemical catalytic activity surface area of 42.9 m2 g-1,with the positive scan peak current density at the catalytic oxidation of methanol in the experiment (ECSA standard) 0.84 mAcm-2, and If/Ib=1.19.Through the improvement of the preparation of Stober particle of silica particles size is 30nm, and the silica bead filled to the pore size of porous alumina template 200nm is used in the filtration method, the composite structure as template is prepared by three kinds of Pt-Ru alloy nanowire materials containing different mass fraction of platinum. Alloy nanowires synthesized 200nm in diameter, and has the pore structure of 30nm. Through the catalytic experiments, the ECSA for three samples are higher than the commercial Pt black catalyst, and has better anti poisoning ability for carbon and lower cost. In three kinds of samples, Pt wt%=50% samples with the highest ECSA=38.3 m2g-1,with the positive scan peak current density at the catalytic oxidation of methanol in the experiment (ECSA standard) 0.52 mAcm-2, and If/Ib=157.