催化学报
催化學報
최화학보
CHINESE JOURNAL OF CATALYSIS
2015年
3期
348-354
,共7页
Salen钼%烯烃环氧化%管状埃洛石%表面修饰%高效催化剂
Salen鉬%烯烴環氧化%管狀埃洛石%錶麵脩飾%高效催化劑
Salen목%희경배양화%관상애락석%표면수식%고효최화제
Salen molybdenum%Alkene epoxidation%Halloysite nanotube%Surface modification%High-efficiency catalyst
采用温和的化学表面改性和自组装方法成功制备了埃洛石纳米管负载salen钼(HNTs-SL-Mo)催化剂,运用透射电镜、X射线衍射、红外光谱、诱导偶合等离子体谱和X射线光电子能谱表征了催化剂的形态、大小和分散性等性质。结果证明了salen结构的存在和埃洛石配位钼催化剂的成功制备。制备的催化剂在各种烯烃的环氧化反应中均有很好的活性,且活性高于均相催化剂。对比实验表明,在固定MoO(O2)2(DMF)2时, salen结构发挥了重要作用,不能用N原子作为单一配体来代替。本文还推测了钼和salen配体可能的连接方式和该催化剂催化烯烃环氧化反应的机理。该催化剂在重复使用8次后其活性未见明显下降,表现出优异的重复使用性能。由于埃洛石是一种廉价易得的材料,因此它可为设计效果独特的催化剂提供一个选择。
採用溫和的化學錶麵改性和自組裝方法成功製備瞭埃洛石納米管負載salen鉬(HNTs-SL-Mo)催化劑,運用透射電鏡、X射線衍射、紅外光譜、誘導偶閤等離子體譜和X射線光電子能譜錶徵瞭催化劑的形態、大小和分散性等性質。結果證明瞭salen結構的存在和埃洛石配位鉬催化劑的成功製備。製備的催化劑在各種烯烴的環氧化反應中均有很好的活性,且活性高于均相催化劑。對比實驗錶明,在固定MoO(O2)2(DMF)2時, salen結構髮揮瞭重要作用,不能用N原子作為單一配體來代替。本文還推測瞭鉬和salen配體可能的連接方式和該催化劑催化烯烴環氧化反應的機理。該催化劑在重複使用8次後其活性未見明顯下降,錶現齣優異的重複使用性能。由于埃洛石是一種廉價易得的材料,因此它可為設計效果獨特的催化劑提供一箇選擇。
채용온화적화학표면개성화자조장방법성공제비료애락석납미관부재salen목(HNTs-SL-Mo)최화제,운용투사전경、X사선연사、홍외광보、유도우합등리자체보화X사선광전자능보표정료최화제적형태、대소화분산성등성질。결과증명료salen결구적존재화애락석배위목최화제적성공제비。제비적최화제재각충희경적배양화반응중균유흔호적활성,차활성고우균상최화제。대비실험표명,재고정MoO(O2)2(DMF)2시, salen결구발휘료중요작용,불능용N원자작위단일배체래대체。본문환추측료목화salen배체가능적련접방식화해최화제최화희경배양화반응적궤리。해최화제재중복사용8차후기활성미견명현하강,표현출우이적중복사용성능。유우애락석시일충렴개역득적재료,인차타가위설계효과독특적최화제제공일개선택。
Halloysite‐nanotube‐supported Mo salen (HNTs‐Mo‐SL) catalysts were successfully prepared using a facile chemical surface modification and self‐assembly method. The morphologies, sizes, structure, and dispersion of the as‐prepared catalysts were investigated by transmission electron microscopy, X‐ray diffraction, and Fourier‐transform infrared, inductively coupled plasma, and X‐ray photoelec‐tron spectroscopy, which confirmed the existence of the Mo salen structure and successful synthesis of the HNTs‐Mo‐SL catalyst. The immobilized catalyst was found to be highly reactive in the epoxi‐dation of a wide range of alkenes, including linear, cyclic, and aromatic alkenes. The immobilized catalyst exhibited a higher catalytic activity for alkene epoxidation than homogeneous Mo. In con‐trast experiments, it was determined that the salen structure played an important role in immobi‐lizing MoO(O2)2(DMF)2 and improving the conversion and efficiency of alkene epoxidation, which could not be obtained using other ligands, such as the N atom as a single ligand. Furthermore, the bonding between Mo and the salen ligands and the possible mechanism of alkene epoxidation cata‐lyzed by the catalyst were determined. The catalyst could be reused several times without signifi‐cant loss of catalytic activity. Given that halloysite nanotubes are cheap and easy to obtain, this cat‐alyst offers a novel alternative for the rational design of catalysts with desired features.