简介：

简介：共沉淀-浸渍法制备Pt／Co-Ba-Al-O样品。采用XRD，XAFS等手段对样品的微观结构进行了详细的表征。载体经过800℃焙烧后，Co物种主要以四面体配位的铝酸钴相存在。铂物种则以小金属原子簇形式存在，分散度很高。添加钴物种对Ba物种存在形态的影响不大；但改善了氧化铝相的分散度：抑制了金属铂原子簇与载体的相互作用，使Pt在催化剂表面分散更均匀。

简介：Inthiswork,thelaserinducedplasmaplumecharacteristicsandsurfacemorphologyofPt-andAg-iondepositedsiliconwerestudied.Thedepositedsiliconwasexposedtocumulativelaserpulses.Theplasmaplumeimagesproducedbyeachlasershotwerecapturedthroughacomputercontrolledimagecapturingsystemandanalyzedwithimage-Jsoftware.Theintegratedopticalemissionintensityofbothsamplesshowedanincreasingtrendwithincreasingpulses.Ag-iondepositedsiliconshowedhigheropticalemissionintensityascomparedtoPt-iondepositedsilicon,suggestingthatmoredamageoccurredtothesiliconbyAgions,whichwasconfirmedbySRIM/TRIMsimulations.Thesurfacemorphologiesofbothsampleswereexaminedbyopticalmicroscopeshowingthermal,exfoliationalandhydrodynamicalsputteringprocessesalongwiththere-depositionofthematerial,debrisandheataffectedzones’formation.ThecraterofPt-iondepositedsiliconwasdeeperbuthadlesslateraldamagethanAgiondepositedsilicon.Thenovelresultsclearlyindicatedthattheiondepositedsiliconsurfaceproducedincubationcenters,whichledtomoreabsorptionofincidentlightresultingintoahigheremissionintensityfromtheplasmaplumeanddeepercraterformationascomparedtopuresilicon.Theapproachcanbeeffectivelyutilizedinthelaserinducedbreakdownspectroscopytechnique,whichendurespoorlimitsofdetection.

简介：采用等量共浸和分步浸制备Co-Pt/γ-Al2O3催化剂。PtL-Ⅲ边的EXAFS结果表明。在氧化态样品中，Pt主要以氯化物形式存在；而在还原态样品中，Pt以氯化物和金属Pt形式共存，共浸法制得的样品中Pt-Cl配位明显，而分步浸法制得的样品中金属Pt为主要存在形式。Co-K边的EXAFS结果表明，氧化态样品中Co主要以Co3O4的形式存在，经氢还原后，Co以高分散的零价钴形式存在。共浸法制得的样品中Pt和Co物种具有更高的分散度。