本文主要研究内容
作者刘国东（2019）在《ZnO改性纳米Silicalite-1沸石表面酸性及催化性能的研究》一文中研究指出：Silicalite-1(S-1)沸石是一种具有MFI拓扑结构的全硅沸石分子筛,该沸石的比表面积较高、热稳定性和水热稳定性较好。但是,由于S-1沸石的酸量很少、酸强度很弱,所以它在催化领域的应用十分有限。另一方面,C3、C4低碳烷烃无氧脱氢反应和C6、C7等链烷烃芳构化反应都具有重要的研究和应用价值。因此,本文围绕增强S-1沸石酸性、研制新型低碳烷烃无氧脱氢和链烷烃芳构化催化剂开展论文研究工作,主要研究内容和结果如下:首先,用浸渍法制备了系列ZnO改性纳米S-1沸石催化剂ZnOx/S-1(1.2≤x≤14.9)。采用NH3-TPD、碱性分子探针(吡啶、氨气)吸附和羟基振动FT-IR光谱法系统研究了ZnOx/S-1催化剂的酸性。结果表明,纳米S-1沸石经ZnO改性后,其总酸量显著增加。其中,ZnO10.0/S-1催化剂的总酸量约为纳米S-1沸石母体的40倍。虽然ZnOx/S-1催化剂的酸强度明显强于纳米S-1沸石,但仍属于弱酸范畴。ZnOx/S-1催化剂表面既有Lewis酸也有Br(?)nsted酸。FT-IR表征和量化计算研究表明,ZnOx/S-1催化剂上的Br(?)nsted酸中心与落位于S-1孔道内亚纳米ZnO簇上的表面锌羟基[Zn-OH]+有关。而表面锌羟基[Zn-OH]+的生成可能与S-1沸石表面硅羟基向亚纳米ZnO簇转移H质子有关。这种在改性过程中产生的锌羟基[Zn-OH]+属于ZnOx/S-1催化剂的固有Br(?)nsted酸中心。此外,异丁烷吸附FT-IR光谱研究还发现ZnOx/S-1催化剂在解离活化烷烃分子时,其亚纳米ZnO簇上能够生成伴生锌羟基[Zn-OH]+,从而产生伴生Br(?)nsted酸中心。其次,以异丁烷为探针分子,采用固定床反应装置考察了 ZnOx/S-1催化剂对低碳烷烃无氧脱氢转化的催化性能。结果表明,在550℃,i-C4H10/N2=1:1(V/V),混合气体空速GHSV=1200 h-1的条件下,异丁烷在S-1沸石上基本不转化,但在ZnOx/S-1(3.7≤x≤14.9)催化剂上的转化率可达60.2%～66.7%,总丁烯选择性可达84.6%～90.9%。异丁烷转化率和总酸量呈线性关系。与ZnO/ZSM-5催化剂相比,ZnOx/S-1催化剂在异丁烷无氧脱氢转化中的裂解副产物选择性明显减少。此外,在异丁烷无氧脱氢转化产物中还检测到大量丁烯异构体和一些芳烃产物。这些结果表明,ZnOx/S-1催化剂上的Br(?)nsted酸中心(锌羟基[Zn-OH]+)具有催化异构化和芳构化反应的能力。在此基础上,采用氯铂酸浸渍法制备了ZnO/S-1负载Pt催化剂(Pt0.1-ZnO7.5/S-1)。该催化剂上有Lewis酸型亚纳米ZnO簇活性中心([Zn-O-Zn]2+)、Br(?)nsted酸活性中心([Zn-OH]+)和金属活性中心(Pt0和PtⅡ),属于金属-酸双功能催化剂。研究表明,负载于ZnO/S-1催化剂上的Pt物种能促进氘气(D2)解离吸附生成的表面氘物种([Zn-OD]+和[Zn-D]+)重组脱附,促进Lewis酸中心([Zn-O-Zn]2+)复原。Pt0.1-ZnO7.5/S-1催化剂具有较高的链烷烃芳构化活性和较好的芳烃产物选择性。在500 ℃和1.0 atm下,正己烷探针分子在上述负载Pt催化剂上的脉冲反应转化率为61.4%,苯选择性为71.5%。而在相同条件下,Zn07.5/S-1催化剂的对应指标分别为17.1%和40.9%;传统重整催化剂Pt0.3-Re0.3/A1203-C11.0的对应指标分别为33.3%和51.2%。Pt0.1-ZnO7.5/S-1催化剂不仅具有良好的链烷烃芳构化活性和选择性,还具有良好的抗硫中毒能力。
Abstract
Silicalite-1(S-1)fei dan shi yi chong ju you MFIta pu jie gou de quan gui fei dan fen zi shai ,gai fei dan de bi biao mian ji jiao gao 、re wen ding xing he shui re wen ding xing jiao hao 。dan shi ,you yu S-1fei dan de suan liang hen shao 、suan jiang du hen ruo ,suo yi ta zai cui hua ling yu de ying yong shi fen you xian 。ling yi fang mian ,C3、C4di tan wan ting mo yang tuo qing fan ying he C6、C7deng lian wan ting fang gou hua fan ying dou ju you chong yao de yan jiu he ying yong jia zhi 。yin ci ,ben wen wei rao zeng jiang S-1fei dan suan xing 、yan zhi xin xing di tan wan ting mo yang tuo qing he lian wan ting fang gou hua cui hua ji kai zhan lun wen yan jiu gong zuo ,zhu yao yan jiu nei rong he jie guo ru xia :shou xian ,yong jin zi fa zhi bei le ji lie ZnOgai xing na mi S-1fei dan cui hua ji ZnOx/S-1(1.2≤x≤14.9)。cai yong NH3-TPD、jian xing fen zi tan zhen (bi ding 、an qi )xi fu he qiang ji zhen dong FT-IRguang pu fa ji tong yan jiu le ZnOx/S-1cui hua ji de suan xing 。jie guo biao ming ,na mi S-1fei dan jing ZnOgai xing hou ,ji zong suan liang xian zhe zeng jia 。ji zhong ,ZnO10.0/S-1cui hua ji de zong suan liang yao wei na mi S-1fei dan mu ti de 40bei 。sui ran ZnOx/S-1cui hua ji de suan jiang du ming xian jiang yu na mi S-1fei dan ,dan reng shu yu ruo suan fan chou 。ZnOx/S-1cui hua ji biao mian ji you Lewissuan ye you Br(?)nstedsuan 。FT-IRbiao zheng he liang hua ji suan yan jiu biao ming ,ZnOx/S-1cui hua ji shang de Br(?)nstedsuan zhong xin yu la wei yu S-1kong dao nei ya na mi ZnOcu shang de biao mian xin qiang ji [Zn-OH]+you guan 。er biao mian xin qiang ji [Zn-OH]+de sheng cheng ke neng yu S-1fei dan biao mian gui qiang ji xiang ya na mi ZnOcu zhuai yi Hzhi zi you guan 。zhe chong zai gai xing guo cheng zhong chan sheng de xin qiang ji [Zn-OH]+shu yu ZnOx/S-1cui hua ji de gu you Br(?)nstedsuan zhong xin 。ci wai ,yi ding wan xi fu FT-IRguang pu yan jiu hai fa xian ZnOx/S-1cui hua ji zai jie li huo hua wan ting fen zi shi ,ji ya na mi ZnOcu shang neng gou sheng cheng ban sheng xin qiang ji [Zn-OH]+,cong er chan sheng ban sheng Br(?)nstedsuan zhong xin 。ji ci ,yi yi ding wan wei tan zhen fen zi ,cai yong gu ding chuang fan ying zhuang zhi kao cha le ZnOx/S-1cui hua ji dui di tan wan ting mo yang tuo qing zhuai hua de cui hua xing neng 。jie guo biao ming ,zai 550℃,i-C4H10/N2=1:1(V/V),hun ge qi ti kong su GHSV=1200 h-1de tiao jian xia ,yi ding wan zai S-1fei dan shang ji ben bu zhuai hua ,dan zai ZnOx/S-1(3.7≤x≤14.9)cui hua ji shang de zhuai hua lv ke da 60.2%～66.7%,zong ding xi shua ze xing ke da 84.6%～90.9%。yi ding wan zhuai hua lv he zong suan liang cheng xian xing guan ji 。yu ZnO/ZSM-5cui hua ji xiang bi ,ZnOx/S-1cui hua ji zai yi ding wan mo yang tuo qing zhuai hua zhong de lie jie fu chan wu shua ze xing ming xian jian shao 。ci wai ,zai yi ding wan mo yang tuo qing zhuai hua chan wu zhong hai jian ce dao da liang ding xi yi gou ti he yi xie fang ting chan wu 。zhe xie jie guo biao ming ,ZnOx/S-1cui hua ji shang de Br(?)nstedsuan zhong xin (xin qiang ji [Zn-OH]+)ju you cui hua yi gou hua he fang gou hua fan ying de neng li 。zai ci ji chu shang ,cai yong lv bo suan jin zi fa zhi bei le ZnO/S-1fu zai Ptcui hua ji (Pt0.1-ZnO7.5/S-1)。gai cui hua ji shang you Lewissuan xing ya na mi ZnOcu huo xing zhong xin ([Zn-O-Zn]2+)、Br(?)nstedsuan huo xing zhong xin ([Zn-OH]+)he jin shu huo xing zhong xin (Pt0he PtⅡ),shu yu jin shu -suan shuang gong neng cui hua ji 。yan jiu biao ming ,fu zai yu ZnO/S-1cui hua ji shang de Ptwu chong neng cu jin dao qi (D2)jie li xi fu sheng cheng de biao mian dao wu chong ([Zn-OD]+he [Zn-D]+)chong zu tuo fu ,cu jin Lewissuan zhong xin ([Zn-O-Zn]2+)fu yuan 。Pt0.1-ZnO7.5/S-1cui hua ji ju you jiao gao de lian wan ting fang gou hua huo xing he jiao hao de fang ting chan wu shua ze xing 。zai 500 ℃he 1.0 atmxia ,zheng ji wan tan zhen fen zi zai shang shu fu zai Ptcui hua ji shang de mai chong fan ying zhuai hua lv wei 61.4%,ben shua ze xing wei 71.5%。er zai xiang tong tiao jian xia ,Zn07.5/S-1cui hua ji de dui ying zhi biao fen bie wei 17.1%he 40.9%;chuan tong chong zheng cui hua ji Pt0.3-Re0.3/A1203-C11.0de dui ying zhi biao fen bie wei 33.3%he 51.2%。Pt0.1-ZnO7.5/S-1cui hua ji bu jin ju you liang hao de lian wan ting fang gou hua huo xing he shua ze xing ,hai ju you liang hao de kang liu zhong du neng li 。
论文参考文献
论文详细介绍
论文作者分别是来自大连理工大学的刘国东，发表于刊物大连理工大学2019-07-19论文，是一篇关于改性论文,沸石酸性论文,异丁烷无氧脱氢论文,正己烷芳构化论文,大连理工大学2019-07-19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，资料来自大连理工大学2019-07-19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：改性论文; 沸石酸性论文; 异丁烷无氧脱氢论文; 正己烷芳构化论文; 大连理工大学2019-07-19论文;