物理化学学报
物理化學學報
물이화학학보
ACTA PHYSICO-CHIMICA SINICA
2012年
6期
1467-1473
,共7页
邵新超%段林海%武玉叶%秦玉才%于文广%王源%李怀雷%孙兆林%宋丽娟
邵新超%段林海%武玉葉%秦玉纔%于文廣%王源%李懷雷%孫兆林%宋麗娟
소신초%단림해%무옥협%진옥재%우문엄%왕원%리부뢰%손조림%송려연
SBA-15介孔材料%表面酸性%羟基%吸附脱硫%Lewis酸
SBA-15介孔材料%錶麵痠性%羥基%吸附脫硫%Lewis痠
SBA-15개공재료%표면산성%간기%흡부탈류%Lewis산
SBA-15 mesoporous material%Surface acidity%Hydroxyl group%Adsorptive desulfurization%Lewis acid
固相研磨法是将不同量的活性组分掺入到介孔材料上的一种简单有效的方法.采用该法以焙烧脱模前后的SBA-15为载体分别制备了不同负载量的CuO-SBA-15吸附剂.利用X射线衍射(XRD)、N2物理吸附、傅里叶变换红外(FTIR)等方法表征了吸附剂的物理性质.通过原位红外技术考察了改性前后介孔材料表面羟基的变化.借助吡啶-原位傅里叶变换红外(py-FTIR)技术考察了吸附剂表面的酸类型及相对酸量.采用静态吸附实验评价了吸附剂对催化裂化(FCC)燃料油的吸附脱硫性能.结果表明:CuO是与SBA-15表面的Si-OH结合形成[Si-O-Cu-O-Si]交联从而达到分散的目的;以SBA-15介孔材料(APS)为载体能够有效抑制在焙烧过程中介孔材料表面羟基的缩合,且CuO负载量达到3 mmol·g-1时仍能够均匀分散在载体SBA-15上,而采用焙烧脱模的SBA-15 (CS)为载体制备的CuO-SBA-15吸附剂却出现了活性组分团聚现象;吸附剂的酸性与脱硫性能均随着CuO的增加出现先增加后降低的趋势,当CuO负载量达到3 mmol·g-1时吸附剂具有最高的Lewis酸(L酸)酸量及最佳的脱硫性能;吸附剂的L酸酸量与其脱硫性能成正相关关系;另外吸附剂的L酸的形成是由于改性后Cu周围的电荷密度降低引起的.
固相研磨法是將不同量的活性組分摻入到介孔材料上的一種簡單有效的方法.採用該法以焙燒脫模前後的SBA-15為載體分彆製備瞭不同負載量的CuO-SBA-15吸附劑.利用X射線衍射(XRD)、N2物理吸附、傅裏葉變換紅外(FTIR)等方法錶徵瞭吸附劑的物理性質.通過原位紅外技術攷察瞭改性前後介孔材料錶麵羥基的變化.藉助吡啶-原位傅裏葉變換紅外(py-FTIR)技術攷察瞭吸附劑錶麵的痠類型及相對痠量.採用靜態吸附實驗評價瞭吸附劑對催化裂化(FCC)燃料油的吸附脫硫性能.結果錶明:CuO是與SBA-15錶麵的Si-OH結閤形成[Si-O-Cu-O-Si]交聯從而達到分散的目的;以SBA-15介孔材料(APS)為載體能夠有效抑製在焙燒過程中介孔材料錶麵羥基的縮閤,且CuO負載量達到3 mmol·g-1時仍能夠均勻分散在載體SBA-15上,而採用焙燒脫模的SBA-15 (CS)為載體製備的CuO-SBA-15吸附劑卻齣現瞭活性組分糰聚現象;吸附劑的痠性與脫硫性能均隨著CuO的增加齣現先增加後降低的趨勢,噹CuO負載量達到3 mmol·g-1時吸附劑具有最高的Lewis痠(L痠)痠量及最佳的脫硫性能;吸附劑的L痠痠量與其脫硫性能成正相關關繫;另外吸附劑的L痠的形成是由于改性後Cu週圍的電荷密度降低引起的.
고상연마법시장불동량적활성조분참입도개공재료상적일충간단유효적방법.채용해법이배소탈모전후적SBA-15위재체분별제비료불동부재량적CuO-SBA-15흡부제.이용X사선연사(XRD)、N2물리흡부、부리협변환홍외(FTIR)등방법표정료흡부제적물이성질.통과원위홍외기술고찰료개성전후개공재료표면간기적변화.차조필정-원위부리협변환홍외(py-FTIR)기술고찰료흡부제표면적산류형급상대산량.채용정태흡부실험평개료흡부제대최화열화(FCC)연료유적흡부탈류성능.결과표명:CuO시여SBA-15표면적Si-OH결합형성[Si-O-Cu-O-Si]교련종이체도분산적목적;이SBA-15개공재료(APS)위재체능구유효억제재배소과정중개공재료표면간기적축합,차CuO부재량체도3 mmol·g-1시잉능구균균분산재재체SBA-15상,이채용배소탈모적SBA-15 (CS)위재체제비적CuO-SBA-15흡부제각출현료활성조분단취현상;흡부제적산성여탈류성능균수착CuO적증가출현선증가후강저적추세,당CuO부재량체도3 mmol·g-1시흡부제구유최고적Lewis산(L산)산량급최가적탈류성능;흡부제적L산산량여기탈류성능성정상관관계;령외흡부제적L산적형성시유우개성후Cu주위적전하밀도강저인기적.
Solid-state grinding is a simple and effective technique to incorporate active species into the channels of mesoporous materials with different degrees of filling.Using this method,different concentrations of CuO were loaded into the mesochannels of as-prepared mesoporous silica (APS) and calcined SBA-15 (CS).The samples were prepared and characterized using X-ray diffraction (XRD),N2 physisorption,and Fourier transform infrared (FTIR) spectroscopy.The relative number of hydroxyl groups was studied by in situ FTIR spectroscopy,and the total surface acidity of the adsorbents was monitored by FTIR spectroscopy at 423 K using pyridine as a probe.Desulfurization of fluid catalytic cracking (FCC) fuel oils using these materials was investigated.The results suggest that CuO interacts directly with support hydroxyl groups to form [Si-O-Cu-O-Si] linkages in the mixtures,which can effectively constrain the condensation of hydroxyl groups in SBA-15 to improve the mesostructure of the adsorbents during calcination.Saturated coverage of the surface of APS is reached using 3 mmol· g-1 CuO.However,using CS,aggregation of CuO is observed in the material containing 3 mmol ·g-1 of CuO.Both the surface acidity and desulfurization performance significantly increase upon modification of SBA-15 with CuO,and then decrease slowly as the concentration of CuO is increased.The sample containing 3 mmol· g-1 CuO shows the highest Lewis acidity and desulfurization performance.The Lewis acidity of the adsorbents matches the adsorptive desulfurization performance.It is also demonstrated that reduction of charge density around copper atoms helps to form Lewis acid sites.