催化剂表征方法

技术官员村位于位于亚运城东部，主干道二以东石楼涌以西的地块，占地面积、m2，总建筑面积、m2，共包括地下室南区、地下室北区、地上部分1栋～12栋、服务中心、室外工程等多个单体工程。其中住宅面积m2，共12栋，1～7栋建筑层数为11层，8～12栋11层（局部复式顶层），首层局部架空，布置公建配套设施。integratedenergy,chemicalsandtextileYibincity,arethethreecorepillarsoftheindustry.In2014,thewuliangyebrandvalueto73.58billionyuan,thecity'sliquorindustrysliptostabilise.Promotingdeepdevelopmentofintegratedenergy,advancedequipmentmanufacturingindustry,changningdistrict,shalegasproductioncapacityreached277millioncubicmetres,builtthecountry'sfirstindependenthigh-yieldwellsandpipelinesinthefirstsection,theleadinfactoryproductionandsupplytothepopulation.2.1-3GDPgrowthfigure2.1-4Yibin,Yibincity,Yibincity,fiscalrevenuegrowth2.1.4topographyterrainoverallisSouthwest,North-EasternState.Lowmountainsandhillsinthecitylandscapeasthemainridge-and-Valley,pingbasmallfragmentednaturepictureforwaterandthesecondlandofthesevenhills.236metersto2000metersabovesealevelinthecity,lowmountain,46.6%hills45.3%,pingbaonly8.1%.2.1.5developmentofYibinlandscapesanddistinctivefeatureinthecenterofthecity,withlimitations,andspatialstructureoftypicalzonalgroup,2012-citiesinbuildingwithanareaofabout76.2km2.Fromcity-buildingsituation,oldtown-theSouthBankCenterconstructionislaggingbehind,disintegrationoftheoldcityisslow,optimizationandupgrading,qualitypublicserviceresourcesarestillheavilyconcentratedintheoldtowntogether.SouthbankCentrehasnotbeenformed,functionsoftheserviceareaspaceismissing.Meanwhile,peripheralgroupcentresservicewasweakandinadequateaccountingforcitydevelopment,suspiciouspatterncouldnotbeformed.Asregardstransport,withtheoutwardexpansionofcities,citieshavebeenexpanding,centripetalcitytrafficorganizationhasnotchanged,integratedenergy,chemicalsandtextileYibincity,arethethreecorepillarsoftheindustry.In2014,thewuliangyebrandvalueto73.58billionyuan,thecity'sliquorindustrysliptostabilise.Promotingdeepdevelopmentofintegratedenergy,advancedequipmentmanufacturingindustry,changningdistrict,shalegasproductioncapacityreached277millioncubicmetres,builtthecountry'sfirstindependenthigh-yieldwellsandpipelinesinthefirstsection,theleadinfactoryproductionandsupplytothepopulation.2.1-3GDPgrowthfigure2.1-4Yibin,Yibincity,Yibincity,fiscalrevenuegrowth2.1.4topographyterrainoverallisSouthwest,North-EasternState.Lowmountainsandhillsinthecitylandscapeasthemainridge-and-Valley,pingbasmallfragmentednaturepictureforwaterandthesecondlandofthesevenhills.236metersto2000metersabovesealevelinthecity,lowmountain,46.6%hills45.3%,pingbaonly8.1%.2.1.5developmentofYibinlandscapesanddistinctivefeatureinthecenterofthecity,withlimitations,andspatialstructureoftypicalzonalgroup,2012-citiesinbuildingwithanareaofabout76.2km2.Fromcity-buildingsituation,oldtown-theSouthBankCenterconstructionislaggingbehind,disintegrationoftheoldcityisslow,optimizationandupgrading,qualitypublicserviceresourcesarestillheavilyconcentratedintheoldtowntogether.SouthbankCentrehasnotbeenformed,functionsoftheserviceareaspaceismissing.Meanwhile,peripheralgroupcentresservicewasweakandinadequateaccountingforcitydevelopment,suspiciouspatterncouldnotbeformed.Asregardstransport,withtheoutwardexpansionofcities,citieshavebeenexpanding,centripetalcitytrafficorganizationhasnotchanged,1.2比表面测试单位重量催化剂所具有的表面积称为比表面，其中具有活性的表面称活性比表面，也称有效比表面。尽管催化剂的活性、选择性以及稳定性等主要取决于催化剂的化学结构，但其在很大程度上也受到催化剂的某些物理性质如催化剂的表面积的影响。一般认为，催化剂表面积越大，其上所含有的活性中心越多，催化剂的活性也越高。因此，测定、表征催化剂的比表面对考察催化剂的活性等性能具有很大的意义和实际应用价值。催化剂的表面积针对反应来说可以分为总比表面和活性比表面，总比表面可用物理吸附的方法测定，而活性比表面则可采用化学吸附的方法测定。催化剂的比表面积的常见表征方法见表2。1.2.1总表面积的测定催化剂总表面积的测定目前所采用的方法基本上均为低温物理吸附法，而其中的BET法则更是推崇为催化剂表面积测定的标准方法。有关BET法的具体介绍见第二章，在此不展开讨论。1.2.2有效表面积的测定BET法测定的是催化剂的总表面积。但是在实际应用中，催化剂的表面中通常只是其中的一部分才具有活性，这部分称为活性表面。活性表面的面积测定通常采用“选择化学吸附”进行测定。如附载型金属催化剂，其上暴露的金属表面是催化活性的，以氢、一氧化碳为吸附质进行选择化学吸附，即可测定活性金属表面积，因为氢、一氧化碳只与催化剂上的金属发生化学吸附作用，而载体对这类气体的吸附可以忽略不计。同样，用碱性气体的选择化学吸附可测定催化剂上酸性中心所具有的表面积。表2列出了用于测定催化剂比表面积的常见方法。表2催化剂比表面表征类别测试方法备注总表面积BET法标准方法X-射线小角度法快速测定表面积活性表面积金属化学吸附法H2吸附法不适用于钯催化剂O2吸附法计量数不确定；尤其适用于不容易化学吸附氢或一氧化碳的金属CO吸附法不适合容易生成羰基化合物的金属N2O吸附法尤其适用于负载型铜和银催化剂中金属表面积的测定吸附-滴定法H2-O2滴定法先决条件是先吸附的氧只与活性中心发生吸附作用电子显微镜法困难，对Pt、Pd负载催化剂效果较好X-射线谱线加宽法粗略估计各种晶体组分的表面积氧化物无通用方法，利用各组分在化学吸附性质方面的差异进行测量技术官员村位于位于亚运城东部，主干道二以东石楼涌以西的地块，占地面积、m2，总建筑面积、m2，共包括地下室南区、地下室北区、地上部分1栋～12栋、服务中心、室外工程等多个单体工程。其中住宅面积m2，共12栋，1～7栋建筑层数为11层，8～12栋11层（局部复式顶层），首层局部架空，布置公建配套设施。integratedenergy,chemicalsandtextileYibincity,arethethreecorepillarsoftheindustry.In2014,thewuliangyebrandvalueto73.58billionyuan,thecity'sliquorindustrysliptostabilise.Promotingdeepdevelopmentofintegratedenergy,advancedequipmentmanufacturingindustry,changningdistrict,shalegasproductioncapacityreached277millioncubicmetres,builtthecountry'sfirstindependenthigh-yieldwellsandpipelinesinthefirstsection,theleadinfactoryproductionandsupplytothepopulation.2.1-3GDPgrowthfigure2.1-4Yibin,Yibincity,Yibincity,fiscalrevenuegrowth2.1.4topographyterrainoverallisSouthwest,North-EasternState.Lowmountainsandhillsinthecitylandscapeasthemainridge-and-Valley,pingbasmallfragmentednaturepictureforwaterandthesecondlandofthesevenhills.236metersto2000metersabovesealevelinthecity,lowmou