李永霞,孫金魚,任光明
(山西忻州師范學(xué)院化學(xué)系,材料計算化學(xué)山西省高等學(xué)校重點實驗室,
山西 忻州 034000)
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李永霞*,孫金魚,任光明
(山西忻州師范學(xué)院化學(xué)系,材料計算化學(xué)山西省高等學(xué)校重點實驗室,
山西 忻州 034000)
摘要:以尿素為沉淀劑,檸檬酸鈉為絡(luò)合劑,采用均相沉淀法制備-LDHs。以制備的-LDHs為前驅(qū)體,分別與NaCl和對甲苯磺酸鈉進(jìn)行離子交換反應(yīng)得到-LDHs新型催化劑,成功實現(xiàn)對甲苯磺酸根負(fù)載Ni(2+)-Fe(3+)-LDHs。研究表明,為介孔材料,比表面積為165.6 m2·g(-1),平均孔徑為14.7 nm,較大比表面積和空隙結(jié)構(gòu)增強了其吸附性能和催化活性。
關(guān)鍵詞:催化化學(xué);類水滑石;對甲苯磺酸鈉;催化劑
水滑石(LDHs)是一種典型的多功能陰離子層狀化合物,由正電荷的層板主體和帶負(fù)電荷的層間客體疊加復(fù)合而成[1]。LDHs特有的層板結(jié)構(gòu)使其具有微孔結(jié)構(gòu)、較大BET比表面積和較高催化反應(yīng)活性[2]。LDHs具有陰離子可交換性,可將一些功能性客體陰離子引至LDHs層間[3]。在LDHs材料層間插入功能性陰離子是一種定向合成和功能改性技術(shù)[4],可以系統(tǒng)調(diào)控目標(biāo)產(chǎn)物的物化性能,由此得到所期望的新材料。
對甲苯磺酸作為酯化反應(yīng)催化劑時,活性高,選擇性好,用量少,廣泛用于化工合成和酯化反應(yīng)[5]。但腐蝕設(shè)備較嚴(yán)重,回收比較困難。將對甲苯磺酸根離子負(fù)載到催化活性較高的Ni2+-Fe3+-LDHs層間,利用Ni2+-Fe3+-LDHs層板間限域作用以及對甲苯磺酸根與帶正電荷層板強的靜電作用力,可使對甲苯磺酸根牢牢固定在Ni2+-Fe3+-LDHs層間,提高催化性能。
1實驗部分
1.1試劑和儀器
尿素、NiCl2·6H2O、FeCl3·6H2O、乙醇、對甲苯磺酸鈉、檸檬酸鈉和乙酸均為分析純試劑。
STA1700型馬弗爐,鄭州晨星耐火材料有限公司;101-4B型數(shù)顯電熱恒溫鼓風(fēng)干燥箱,上海葉拓儀器儀表有限公司;JB-1B型磁力攪拌器,上海雷磁儀電科學(xué)儀器股份有限公司。
1.2表征
采用日本島津公司600型XRD對樣品進(jìn)行物相分析,CuKα,λ=0.154 06 nm,Ni濾波,工作電流40 mA,工作電壓40 kV,掃描速率5°·min-1,掃描范圍2°~70°。
采用德國布魯克公司TENSOR27型紅外光譜儀,溴化鉀壓片法表征試樣的層間陰離子種類,掃描范圍(400~4 000) cm-1。
采用美國康塔儀器公司Autosorb-iQ全自動比表面和孔徑分布分析儀對樣品的微孔結(jié)構(gòu)進(jìn)行測定。
采用美國FEI公司Quanta 250場發(fā)射掃描電鏡對樣品的形貌進(jìn)行觀察分析。
1.4Ni2+-Fe3+-Cl--LDHs的制備
1.5Ni2+-Fe3+-C7H7SO-3-LDHs的制備
2結(jié)果與討論
圖的XRD圖Figure 1 XRD pattern of -LDHs
圖的SEM照片
圖的FT-IR譜圖Figure 3 FT-IR spectrum of -LDHs
圖 4 不同陰離子插層Ni2+-Fe3+-LDHs的XRD圖Figure 4 XRD patterns of Ni2+-Fe3+-LDHs with different intercalated anions
圖 5 不同陰離子插層Ni2+-Fe3+-LDHs的FT-IR譜圖Figure 5 FT-IR spectra of Ni2+-Fe3+-LDHs with different intercalated anions
圖的N2吸附-脫附等溫曲線Figure 6 N2 adsorption-desorption isotherms of -LDHs
3結(jié)論
參考文獻(xiàn):
[1]Liu Z,Ma R,Ebina Y,et al.General synthesis and delamination of highly crystalline transition-metal-bearing layered double hydroxides[J].Langmuir,2007,23(2):861-867.
[2]Cavani F,Trifiro F,Vaccari A.Hydrotalcite-type anionic clays:preparation,properties and applications[J].Catalysis
Today,1991,11(2):173-301.
[3]Meyn M,Beneke K,Lagaly G.Anion-exchange reactions of layered double hydroxides[J].Inorganic Chemistry,1990,29(26):5201-5207.
[4]陸軍,劉曉磊,史文穎,等.水滑石類插層組裝功能材料[J].石油化工,2008,37(6):539-546.
Lu Jun,Liu Xiaolei,Shi Wenying,et al.Funtion materials of intercalated assembling layered double hydroxides[J].China Petroleum Processing and Petrochemical Technology,2008,37(6):539-546.
[5]張曉玲,金春英,林金清.對甲苯磺酸季銨鹽離子液體催化酯交換反應(yīng)制備生物柴油[J].高校化學(xué)工程學(xué)報,2013,27(5):866-871.
Zhang Xiaoling,Jin Chunying,Lin Jinqing.Transesterification of glycerol trioleate to biodiesel catalyzed byp-toluenesulfonic acid quaternary ammonium ionic liquids[J].Journal of Chemical Engineering of Chinese Universities,2013,27(5):866-871.
[7]馬向榮,李健,黨睿,等.Ni-Mg-Al-LDHs 的制備及其催化酯化高酸原油脫酸的研究[J].應(yīng)用化工,2013,42(1):30-32.
Ma Xiangrong,Li Jian,Dang Rui,et al.Preparation of Ni-Mg-Al-LDHs materials and removal of naphthenic acids from high acid crude oil through catalytic esterfication on Ni-Mg-Al-LDHs[J].Applied Chemical Industry,2013,42(1):30-32.
[8]馬向榮,劉潔瑩.磷鎢雜多酸插層Ni2+-Mg2+-Al3+-LDHs復(fù)合材料的合成[J].工業(yè)催化,2013,21(9):43-45.
Ma Xiangrong,Liu Jieying.Preparation of phosphotungstic heteropoly acid pillared Ni2+-Mg2+-Al3+-LDHs[J].Industrial Catalysis,2013,21(9):43-45.
[10]馬向榮,李紅娟,張智芳,等.十二烷基磺酸根插層Ni2+-Fe3+/Co2+-Ni2+-Fe3+-LDHs及其結(jié)構(gòu)研究[J].應(yīng)用化工,2013,40(6):1007-1014.
Ma Xiangrong,Li Hongjuan,Zhang Zhifang,et al.Preparation and structure of dodecyl sulfonate-pillared Ni2+-Fe3+/Co2+-Ni2+-Fe3+- LDHs[J].Applied Chemical Industry,2013,40(6):1007-1014.
[11]Xu Xiang,Halidou I Hima,Hui Wang,et al.Facile synthesis and catalytic properties of nickel-based mixed-metal oxides with mesopore networks from a novel hybrid composite precursor[J].Chemistry of Materials,2008,20(3):1173-1182.
LiYongxia*,SunJinyu,RenGuangming
(Department of Chemistry, Higher Education Key Laboratory of Materials and Computational Chemistry in Shanxi Province, Xinzhou Teachers University, Xinzhou 034000, Shanxi, China)
Abstract:Using urea as the precipitant and sodium citrate as the chelating -LDHs was prepared by homogeneous precipitation method.Using -LDHs as the -LDHs was synthesized through ion exchange with NaCl and C7H7SO3Na,respectively.The experimental results showed that -LDHs was mesoporous material,and its BET surface area and average pore size were 165.6 m2·g(-1) and 14.7 nm,respectively.The adsorption performance and catalytic activity of the catalyst were enhanced due to its larger specific surface area and pore structure.
Key words:catalytic chemistry;hydrotalcite-like compounds; toluene-p-sulfonic acid sodium; -LDHs catalyst
中圖分類號:O643.36;TQ426.6
文獻(xiàn)標(biāo)識碼:A
文章編號:1008-1143(2016)02-0041-05
doi:10.3969/j.issn.1008-1143.2016.02.008 10.3969/j.issn.1008-1143.2016.02.008
作者簡介:李永霞,1983年生,女,山西省忻州市人,碩士,主要從事化工催化劑及類水滑石材料的研發(fā)。
收稿日期:2015-12-15
CLC number:O643.36;TQ426.6Document code: AArticle ID: 1008-1143(2016)02-0041-05
催化劑制備與研究
通訊聯(lián)系人:李永霞。