Pvd Technology To Prepare Platinum-based Ce-doped Thin Films And Their Structural Study

Energy is an important material foundation of human life, national economy and development of science and technology, the development and utilization of highly efficient non-polluting renewable sources of new secondary energy---such as hydrogen is being attached great importance to all countries.In this paper, expounded the reality and necessity of hydrogen energy development and utilization from the status of energy and the environment,and simply introduced the more current technology and recent applications of hydrogen energy preparation. We aim at the mature hydrogen preparation technology of hydrogen sulfide and research& development of hydrogen fuel cell which low-cost development and utilization of aspects of the commercialization focused on,these two aspects of job both subject to the performance,service life and cost-effective of catalyst carrier materials,so we conduct in-depth research to the platinum-based carrier catalyst. The atomic configuration of the platinum has excellent catalytic activity, stability and long service life because of the not been filled empty d orbit. Cerium has unique help catalytic properties, as well as high temperature stability, high activity and high-dispersion and so on, because it has 4f inner electron layer which is not been completely filled. Mixed Cerium and platinum showing very good synergy. Platinum-based carrier catalyst is one of the important class of non-homogeneous catalyst, has excellent physical and chemical properties, has an irreplaceable key role in hydrogen energy field. The direction of their research focused on reducing the volume of contained platinum, enhance catalytic activity, selectivity and stability, in which catalytic activity and selectivity are closely related to the dispersion degree, distribution and oxidation state of active metal.Successfully prepared carbon/silicon carrier doped ceria thin films of platinum-based catalytic materials by Ion beam sputtering method which belong to PVD technology through "multi-purpose high vacuum ion beam sputtering and electron beam evaporation coating machine," which is belong to independent research and development. Analysis surface structure through XRD,use SEM,and TEM to observe surface morphology, analysed thin film surface composition and chemical characterization of the valence by XPS.and tested performance by electrochemical analysis methods.Through a variety of single-factor experiments finally set the conditions for the appropriate experimental parameters, and analysis various experimental parameters on the impact of coating. On this basis,we have optimization of the experimental parameters of preparation,providing guidance basic data for the further development of the carrier of platinum-based rare alloy catalyst materials which has the narrow nanometer scale and scope of particle size distribution in catalytic metal, crystal orientation and surface composition and structure is controllable,containing platinum is low and has high catalytic activity, stability.The thin-film Samples prepared were nano-catalyst thin film materials which vector-type platinum-based doped variable cerium oxides Ce6O11,CeO,CeO2, and formed two solid solution of platinum Cerium Pt2Ce,Pt5Ce. Temperature directly affects the preferential orientation of platinum, When the temperature is 25℃, the Pt<111> orientation is better, When the temperature is 60℃, the Pt<200> orientation is better,but Pt<111> Was strongly inhibited, When the temperature is 180℃, the growth of Pt was basicly balanced.Control the remaining parameters:when temperature is 25℃, auxiliary oxygen flow value is 8sccm, moving a distance is±20mm, screen pressure is 3KV, beam is 60mA,the sample was prepared has better Pt<111> orientation, Ce doping of 2%, more than 95% of the nano-particle size control at less than lOnm, the nano-particles were evenly dispersed, exchange current density≥200mA/cm2,deterioration attenuation<5%/500 h, which shows that the thin films has better catalytic performance and stability.Through Platinum weight-loss method calculated platinum containing.in samples, the results showed that the contained platinum in thin film samples is less than 0.1mg/cm2by this experiment Which reached the expected experiment purposes, it is hopeful to cut down the cost.