催化学报
催化學報
최화학보
CHINESE JOURNAL OF CATALYSIS
2010年
1期
84-89
,共6页
王希涛%毕超%钟顺和%肖秀芬
王希濤%畢超%鐘順和%肖秀芬
왕희도%필초%종순화%초수분
溶胶-凝胶法%浸渍法%介孔磷酸铝%异丁烯%选择氧化
溶膠-凝膠法%浸漬法%介孔燐痠鋁%異丁烯%選擇氧化
용효-응효법%침지법%개공린산려%이정희%선택양화
sol-gel method%impregnation%mesoporous aluminophosphate%isobutene%selective oxidation
分别采用溶胶-凝胶法和等体积浸渍法制备了MoPO-AIPO_4催化剂,考察了钼物种存在状态对催化剂品格氧活性以及异丁烯选择氧化反应性能的影响.N_2吸附-脱附、X射线衍射、高分辨透射电镜、X射线光电子能谱、傅里叶变换红外光谱、程序升温还原和微反实验结果表明,与浸渍法制备的催化剂相比,溶胶-凝胶法制备的MoPO-AlPO_4催化剂为介孔纳米材料,其比表面积和孔数量均有较大程度的提高.在浸渍法制备的催化剂中,钼物种以四面体MoO_4~(2-)和八表面体MoO_6~(6-)形式存在;而在溶胶-凝胶法制备的催化剂中钼物种主要以四面体MoO_4~(2-)的形式存在,并有部分钼物种嵌入到了AlPO_4骨架中.钼物种的种类对异丁烯选择氧化反应的活性和选择性有较大影响.溶胶-凝胶法制备的催化剂由于嵌入AlPO_4骨架中钼物种的存在,异丁烯选择氧化反应性能得到较大提高.
分彆採用溶膠-凝膠法和等體積浸漬法製備瞭MoPO-AIPO_4催化劑,攷察瞭鉬物種存在狀態對催化劑品格氧活性以及異丁烯選擇氧化反應性能的影響.N_2吸附-脫附、X射線衍射、高分辨透射電鏡、X射線光電子能譜、傅裏葉變換紅外光譜、程序升溫還原和微反實驗結果錶明,與浸漬法製備的催化劑相比,溶膠-凝膠法製備的MoPO-AlPO_4催化劑為介孔納米材料,其比錶麵積和孔數量均有較大程度的提高.在浸漬法製備的催化劑中,鉬物種以四麵體MoO_4~(2-)和八錶麵體MoO_6~(6-)形式存在;而在溶膠-凝膠法製備的催化劑中鉬物種主要以四麵體MoO_4~(2-)的形式存在,併有部分鉬物種嵌入到瞭AlPO_4骨架中.鉬物種的種類對異丁烯選擇氧化反應的活性和選擇性有較大影響.溶膠-凝膠法製備的催化劑由于嵌入AlPO_4骨架中鉬物種的存在,異丁烯選擇氧化反應性能得到較大提高.
분별채용용효-응효법화등체적침지법제비료MoPO-AIPO_4최화제,고찰료목물충존재상태대최화제품격양활성이급이정희선택양화반응성능적영향.N_2흡부-탈부、X사선연사、고분변투사전경、X사선광전자능보、부리협변환홍외광보、정서승온환원화미반실험결과표명,여침지법제비적최화제상비,용효-응효법제비적MoPO-AlPO_4최화제위개공납미재료,기비표면적화공수량균유교대정도적제고.재침지법제비적최화제중,목물충이사면체MoO_4~(2-)화팔표면체MoO_6~(6-)형식존재;이재용효-응효법제비적최화제중목물충주요이사면체MoO_4~(2-)적형식존재,병유부분목물충감입도료AlPO_4골가중.목물충적충류대이정희선택양화반응적활성화선택성유교대영향.용효-응효법제비적최화제유우감입AlPO_4골가중목물충적존재,이정희선택양화반응성능득도교대제고.
MoPO-AlPO_4 catalysts were prepared by sol-gel and impregnation methods. The effects of Mo species on crystal lattice oxygen activity and catalytic performance of MoPO-AlPO_4 for selective oxidation of isobutene were investigated. The catalysts were characterized by N_2 adsorption-desorption, X-ray diffraction, high resolution transmission electron microscopy, Fourier transform infrared spectroscopy, and temperature-programmed reduction. The results showed that the MoPO-AlPO_4 prepared by the sol-gel method existed as mesostructured nanoparticles with larger surface area and more pores than the corresponding MoPO-AlPO_4 prepared by the impregnation. Mo species ap-peared in tetrahedrai coordination in the sample prepared by the sol-gel method and in both tetrahedral and octahedrai coordinations in the sample prepared by impregnation. This indicated that the sample prepared by the sol-gel method had better dispersion of Mo species than that prepared by impregnation. The Mo species incorporated-mesoporous AlPO_4 obviously improved the catalytic performance of MoPO-AlPO_4 for selective oxidation of isobutene.