本文主要研究内容
作者谷贝贝(2019)在《方沸石和LZ-276分子筛的制备及其催化性能研究》一文中研究指出:分子筛是一种具有规则孔道且孔径可调的多孔材料,因为具有特殊的微观形貌、丰富的孔道、大的比表面积和稳定的骨架结构,使得其在催化领域有着广泛的应用。金属铜不仅具有与贵金属相似的催化活性,而且在地球上储量更为丰富,价格更为低廉,因此,铜基纳米材料在催化领域掀起了研究热潮。本文将铜纳米粒子(Cu NPs)与分子筛结合并成功制备分子筛基催化剂,并考察其在苯乙烯氧化反应中对产物选择性的影响,进而在苯乙烯氧化反应的基础上,引入CO2与环氧化物的环加成反应,这两个顺序反应合二为一可视为一锅法反应。另外,又通过水热合成方法制备了一种结构更为稳定的分子筛并将其用于一锅法苯乙烯氧化羧化的评价反应中。具体研究内容如下:1.以四丙基氢氧化铵(TPAOH)为有机模板,硅酸(SiO2·nH2O)为硅源,铝酸钠(NaAlO2)为铝源,通过水热合成法制备方沸石ANA,其晶化过程采用程序阶段升温法,得到的样品经高温煅烧之后,利用物理吸附法和高温高压加氢还原技术制得Cu NPs/ANA复合催化剂。通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)、程序升温还原(H2-TPR)和其他手段表征催化剂的形貌、组成以及结构。将此催化剂用于苯乙烯氧化反应中,发现Cu NPs的价态对产物的选择性具有调控作用。考虑到苯乙烯氧化的产物环氧苯乙烷可以与CO2发生环加成以实现CO2的资源化利用,故将ANA用于一锅法合成苯乙烯环状碳酸酯(SC)的反应中,在CO2压力为0.5 MPa、140℃实验条件下反应10 h后,苯乙烯的转化率接近100%,苯乙烯环状碳酸酯的收率达到78.2%。2.使用硅酸(SiO2·nH2O)为硅源,铝酸钠和硫酸铝作为铝源,并且在不添加任何有机模板剂的条件下水热合成分子筛LZ-276,通过SEM、XRD、比表面积及孔径分析、程序升温脱附(TPD)等手段对其进行表征。将LZ-276和共催化剂碘化钾KI应用于苯乙烯氧化羧化反应,通过探索氧源类型、原料配比、反应温度、CO2充入压力和反应时间等参数对催化结果的影响,得到该反应的最优条件为体积比V(苯乙烯:叔丁基过氧化氢)=1:1,CO2压力为0.5 MPa,在140℃反应10 h。在此条件下,苯乙烯转化率接近100%,SC产率为77%,与之前已报道文献相比,本文催化体系的优势是在较低压力下保证了高催化活性,并且该分子筛催化剂在五次循环反应中展现了良好的化学稳定性,不仅目标产物的收率不会显著降低,而且催化剂的结构依然保持完整。基于这些研究工作,提出了LZ-276/KI催化苯乙烯氧化羧化的可能机理,即一锅合成法可视为两步顺序反应法,在反应过程中,LZ-276和KI是协同作用的关系,关键步骤是分子筛LZ-276中提供酸性位点的Al与环氧苯乙烷的氧原子发生配位,与此同时,I-进攻环氧苯乙烷的β-碳原子另其开环,而LZ-276中提供碱性位点的Si原子可以活化热力学很稳定的CO2分子,令其键角小于180°后插入上一步中间体而产生烷基碳酸酯化合物,最终,中间体烷基碳酸酯化合物脱掉碘离子并闭环方可生成目标产物苯乙烯环状碳酸酯。综上所述,两种沸石催化剂在催化反应过程中均表现出良好的催化性能和循环稳定性,这为CO2的资源化利用提供了新方法和新思路,同时也为有效活性物质改性分子筛提供了可能性。
Abstract
fen zi shai shi yi chong ju you gui ze kong dao ju kong jing ke diao de duo kong cai liao ,yin wei ju you te shu de wei guan xing mao 、feng fu de kong dao 、da de bi biao mian ji he wen ding de gu jia jie gou ,shi de ji zai cui hua ling yu you zhao an fan de ying yong 。jin shu tong bu jin ju you yu gui jin shu xiang shi de cui hua huo xing ,er ju zai de qiu shang chu liang geng wei feng fu ,jia ge geng wei di lian ,yin ci ,tong ji na mi cai liao zai cui hua ling yu xian qi le yan jiu re chao 。ben wen jiang tong na mi li zi (Cu NPs)yu fen zi shai jie ge bing cheng gong zhi bei fen zi shai ji cui hua ji ,bing kao cha ji zai ben yi xi yang hua fan ying zhong dui chan wu shua ze xing de ying xiang ,jin er zai ben yi xi yang hua fan ying de ji chu shang ,yin ru CO2yu huan yang hua wu de huan jia cheng fan ying ,zhe liang ge shun xu fan ying ge er wei yi ke shi wei yi guo fa fan ying 。ling wai ,you tong guo shui re ge cheng fang fa zhi bei le yi chong jie gou geng wei wen ding de fen zi shai bing jiang ji yong yu yi guo fa ben yi xi yang hua suo hua de ping jia fan ying zhong 。ju ti yan jiu nei rong ru xia :1.yi si bing ji qing yang hua an (TPAOH)wei you ji mo ban ,gui suan (SiO2·nH2O)wei gui yuan ,lv suan na (NaAlO2)wei lv yuan ,tong guo shui re ge cheng fa zhi bei fang fei dan ANA,ji jing hua guo cheng cai yong cheng xu jie duan sheng wen fa ,de dao de yang pin jing gao wen duan shao zhi hou ,li yong wu li xi fu fa he gao wen gao ya jia qing hai yuan ji shu zhi de Cu NPs/ANAfu ge cui hua ji 。tong guo sao miao dian zi xian wei jing (SEM)、tou she dian zi xian wei jing (TEM)、Xshe xian yan she (XRD)、Xshe xian guang dian zi neng pu (XPS)、cheng xu sheng wen hai yuan (H2-TPR)he ji ta shou duan biao zheng cui hua ji de xing mao 、zu cheng yi ji jie gou 。jiang ci cui hua ji yong yu ben yi xi yang hua fan ying zhong ,fa xian Cu NPsde jia tai dui chan wu de shua ze xing ju you diao kong zuo yong 。kao lv dao ben yi xi yang hua de chan wu huan yang ben yi wan ke yi yu CO2fa sheng huan jia cheng yi shi xian CO2de zi yuan hua li yong ,gu jiang ANAyong yu yi guo fa ge cheng ben yi xi huan zhuang tan suan zhi (SC)de fan ying zhong ,zai CO2ya li wei 0.5 MPa、140℃shi yan tiao jian xia fan ying 10 hhou ,ben yi xi de zhuai hua lv jie jin 100%,ben yi xi huan zhuang tan suan zhi de shou lv da dao 78.2%。2.shi yong gui suan (SiO2·nH2O)wei gui yuan ,lv suan na he liu suan lv zuo wei lv yuan ,bing ju zai bu tian jia ren he you ji mo ban ji de tiao jian xia shui re ge cheng fen zi shai LZ-276,tong guo SEM、XRD、bi biao mian ji ji kong jing fen xi 、cheng xu sheng wen tuo fu (TPD)deng shou duan dui ji jin hang biao zheng 。jiang LZ-276he gong cui hua ji dian hua jia KIying yong yu ben yi xi yang hua suo hua fan ying ,tong guo tan suo yang yuan lei xing 、yuan liao pei bi 、fan ying wen du 、CO2chong ru ya li he fan ying shi jian deng can shu dui cui hua jie guo de ying xiang ,de dao gai fan ying de zui you tiao jian wei ti ji bi V(ben yi xi :shu ding ji guo yang hua qing )=1:1,CO2ya li wei 0.5 MPa,zai 140℃fan ying 10 h。zai ci tiao jian xia ,ben yi xi zhuai hua lv jie jin 100%,SCchan lv wei 77%,yu zhi qian yi bao dao wen suo xiang bi ,ben wen cui hua ti ji de you shi shi zai jiao di ya li xia bao zheng le gao cui hua huo xing ,bing ju gai fen zi shai cui hua ji zai wu ci xun huan fan ying zhong zhan xian le liang hao de hua xue wen ding xing ,bu jin mu biao chan wu de shou lv bu hui xian zhe jiang di ,er ju cui hua ji de jie gou yi ran bao chi wan zheng 。ji yu zhe xie yan jiu gong zuo ,di chu le LZ-276/KIcui hua ben yi xi yang hua suo hua de ke neng ji li ,ji yi guo ge cheng fa ke shi wei liang bu shun xu fan ying fa ,zai fan ying guo cheng zhong ,LZ-276he KIshi xie tong zuo yong de guan ji ,guan jian bu zhou shi fen zi shai LZ-276zhong di gong suan xing wei dian de Alyu huan yang ben yi wan de yang yuan zi fa sheng pei wei ,yu ci tong shi ,I-jin gong huan yang ben yi wan de β-tan yuan zi ling ji kai huan ,er LZ-276zhong di gong jian xing wei dian de Siyuan zi ke yi huo hua re li xue hen wen ding de CO2fen zi ,ling ji jian jiao xiao yu 180°hou cha ru shang yi bu zhong jian ti er chan sheng wan ji tan suan zhi hua ge wu ,zui zhong ,zhong jian ti wan ji tan suan zhi hua ge wu tuo diao dian li zi bing bi huan fang ke sheng cheng mu biao chan wu ben yi xi huan zhuang tan suan zhi 。zeng shang suo shu ,liang chong fei dan cui hua ji zai cui hua fan ying guo cheng zhong jun biao xian chu liang hao de cui hua xing neng he xun huan wen ding xing ,zhe wei CO2de zi yuan hua li yong di gong le xin fang fa he xin sai lu ,tong shi ye wei you xiao huo xing wu zhi gai xing fen zi shai di gong le ke neng xing 。
论文参考文献
论文详细介绍
论文作者分别是来自内蒙古工业大学的谷贝贝,发表于刊物内蒙古工业大学2019-10-18论文,是一篇关于分子筛论文,铜基催化剂论文,苯乙烯氧化论文,一锅合成法论文,苯乙烯环状碳酸酯论文,内蒙古工业大学2019-10-18论文的文章。本文可供学术参考使用,各位学者可以免费参考阅读下载,文章观点不代表本站观点,资料来自内蒙古工业大学2019-10-18论文网站,若本站收录的文献无意侵犯了您的著作版权,请联系我们删除。
标签:分子筛论文; 铜基催化剂论文; 苯乙烯氧化论文; 一锅合成法论文; 苯乙烯环状碳酸酯论文; 内蒙古工业大学2019-10-18论文;