本文主要研究内容
作者王巍(2019)在《氟代羟基磷灰石改性及其催化尿素醇解反应过程研究》一文中研究指出:羟基磷灰石(Hydroxyapatite,HAP)具有良好的生物相容性,在医学材料、药物载体、吸附材料、涂层等领域得到越来越多的应用。由于其难溶于水和多数有机溶剂,水热稳定性好,可以自主调控形貌,表面具有丰富的酸碱位点和离子交换位点,使得羟基磷灰石可以分散及负载各种金属、配合物分子,在催化领域获得了越来越多的应用。氟代羟基磷灰石(Fluorapatite,FAP)是羟基磷灰石通过离子交换将OH替换成F的衍生物之一,除具有与羟基磷灰石相似的晶体结构和特性外,它还具有更低的溶解度和更高的热稳定性,在催化领域的应用潜力更明显。随着不可再生化石资源的急剧消耗和环境问题的日益严重,人们对清洁可再生新能源的开发迫在眉睫,高酯化产品应用得到重视。以尿素为原料,尿素醇解法制备如碳酸酯类、氨基甲酸酯类等重要的酯类产品具有反应过程清洁、原料来源广泛、廉价易得、反应流程短及反应效率高等显著特点,可以有效的降低工业化制备酯类产物的生产成本,过程的副产物氨气可回收利用,因此过程可实现零排放。但高效、稳定的环保型催化剂的开发一直是尿素醇解反应过程需要突破的关键技术问题。针对于此,本论文首次较系统地研究了改性FAP的可控制备及其催化系列尿素醇解反应制备碳酸酯及氨基甲酸酯的活性规律,获得了如下主要研究结果。1以β-环糊精为模板剂,通过模板法成功地制出比表面积较大的类球型FAP材料,其比表面积由17 m2/g增加到46.4 m2/g,FAP由六棱柱变成类球形。2通过模板-共沉淀法将过渡金属离子(Co,Ni,Cu,Zn)引入FAP结构中,改变过渡金属的种类和过渡金属与氟磷灰石中Ca2+的配比,实现了改性FAP碱度的可控调节,使其可用于酸、碱双中心催化的反应体系。3考察了过渡金属改性FAP催化剂对尿素醇解合成碳酸二甲酯(Dimethyl carbonate,DMC)催化活性变化规律和合成过程的热力学规律。催化剂的酸碱性显著影响催化活性。获得最佳的反应工艺条件为:ZnCa9(PO4)6F2为催化剂,8 h,180℃,尿素6.0 g,甲醇与尿素摩尔比为20:1,催化剂2.4 g,此时尿素的转化率为87.6%,碳酸二甲酯的产率为34.8%,选择性39.7%。5次重复使用实验表明,催化剂具有优良的活性稳定性。4考察了过渡金属改性FAP催化剂对尿素醇解合成醇解制备氨基甲酸甲酯(Methyl carbamate,MC)的过程热力学规律及催化活性变化规律。催化剂的碱性大小对活性有显著影响,以Zn5Ca5(PO4)6F2的活性为最高。确定了反应的最佳工艺条件为:140℃,3 h,尿素6.0 g,催化剂0.3 g,甲醇与尿素摩尔比10:1,此时尿素转化率100%,氨基甲酸甲酯产率98.5%。5次重复使用实验表明,催化剂具有优良的活性稳定性。5确定了ZnCa9(PO4)6F2催化苯胺尿素醇解制备苯氨基甲酸甲酯(Methyl N-phenyl carbamate,MPC)的工艺条件对活性的影响关系,获得了最佳的工艺条件为:180℃,6h,苯胺20 mmol,尿素与苯胺摩尔比为5:1,甲醇与苯胺摩尔比为2:1,催化剂8.0 mmol在此条件下,苯胺转化率94.4%,苯氨基甲酸甲酯选择性75.8%。本论文的研究结果对FAP酸碱中心调控制备及催化应用具有较好的学术及工业应用参考价值,拓展了环保催化剂氟磷灰石的应用领域。
Abstract
qiang ji lin hui dan (Hydroxyapatite,HAP)ju you liang hao de sheng wu xiang rong xing ,zai yi xue cai liao 、yao wu zai ti 、xi fu cai liao 、tu ceng deng ling yu de dao yue lai yue duo de ying yong 。you yu ji nan rong yu shui he duo shu you ji rong ji ,shui re wen ding xing hao ,ke yi zi zhu diao kong xing mao ,biao mian ju you feng fu de suan jian wei dian he li zi jiao huan wei dian ,shi de qiang ji lin hui dan ke yi fen san ji fu zai ge chong jin shu 、pei ge wu fen zi ,zai cui hua ling yu huo de le yue lai yue duo de ying yong 。fu dai qiang ji lin hui dan (Fluorapatite,FAP)shi qiang ji lin hui dan tong guo li zi jiao huan jiang OHti huan cheng Fde yan sheng wu zhi yi ,chu ju you yu qiang ji lin hui dan xiang shi de jing ti jie gou he te xing wai ,ta hai ju you geng di de rong jie du he geng gao de re wen ding xing ,zai cui hua ling yu de ying yong qian li geng ming xian 。sui zhao bu ke zai sheng hua dan zi yuan de ji ju xiao hao he huan jing wen ti de ri yi yan chong ,ren men dui qing jie ke zai sheng xin neng yuan de kai fa pai zai mei jie ,gao zhi hua chan pin ying yong de dao chong shi 。yi niao su wei yuan liao ,niao su chun jie fa zhi bei ru tan suan zhi lei 、an ji jia suan zhi lei deng chong yao de zhi lei chan pin ju you fan ying guo cheng qing jie 、yuan liao lai yuan an fan 、lian jia yi de 、fan ying liu cheng duan ji fan ying xiao lv gao deng xian zhe te dian ,ke yi you xiao de jiang di gong ye hua zhi bei zhi lei chan wu de sheng chan cheng ben ,guo cheng de fu chan wu an qi ke hui shou li yong ,yin ci guo cheng ke shi xian ling pai fang 。dan gao xiao 、wen ding de huan bao xing cui hua ji de kai fa yi zhi shi niao su chun jie fan ying guo cheng xu yao tu po de guan jian ji shu wen ti 。zhen dui yu ci ,ben lun wen shou ci jiao ji tong de yan jiu le gai xing FAPde ke kong zhi bei ji ji cui hua ji lie niao su chun jie fan ying zhi bei tan suan zhi ji an ji jia suan zhi de huo xing gui lv ,huo de le ru xia zhu yao yan jiu jie guo 。1yi β-huan hu jing wei mo ban ji ,tong guo mo ban fa cheng gong de zhi chu bi biao mian ji jiao da de lei qiu xing FAPcai liao ,ji bi biao mian ji you 17 m2/gzeng jia dao 46.4 m2/g,FAPyou liu leng zhu bian cheng lei qiu xing 。2tong guo mo ban -gong chen dian fa jiang guo du jin shu li zi (Co,Ni,Cu,Zn)yin ru FAPjie gou zhong ,gai bian guo du jin shu de chong lei he guo du jin shu yu fu lin hui dan zhong Ca2+de pei bi ,shi xian le gai xing FAPjian du de ke kong diao jie ,shi ji ke yong yu suan 、jian shuang zhong xin cui hua de fan ying ti ji 。3kao cha le guo du jin shu gai xing FAPcui hua ji dui niao su chun jie ge cheng tan suan er jia zhi (Dimethyl carbonate,DMC)cui hua huo xing bian hua gui lv he ge cheng guo cheng de re li xue gui lv 。cui hua ji de suan jian xing xian zhe ying xiang cui hua huo xing 。huo de zui jia de fan ying gong yi tiao jian wei :ZnCa9(PO4)6F2wei cui hua ji ,8 h,180℃,niao su 6.0 g,jia chun yu niao su ma er bi wei 20:1,cui hua ji 2.4 g,ci shi niao su de zhuai hua lv wei 87.6%,tan suan er jia zhi de chan lv wei 34.8%,shua ze xing 39.7%。5ci chong fu shi yong shi yan biao ming ,cui hua ji ju you you liang de huo xing wen ding xing 。4kao cha le guo du jin shu gai xing FAPcui hua ji dui niao su chun jie ge cheng chun jie zhi bei an ji jia suan jia zhi (Methyl carbamate,MC)de guo cheng re li xue gui lv ji cui hua huo xing bian hua gui lv 。cui hua ji de jian xing da xiao dui huo xing you xian zhe ying xiang ,yi Zn5Ca5(PO4)6F2de huo xing wei zui gao 。que ding le fan ying de zui jia gong yi tiao jian wei :140℃,3 h,niao su 6.0 g,cui hua ji 0.3 g,jia chun yu niao su ma er bi 10:1,ci shi niao su zhuai hua lv 100%,an ji jia suan jia zhi chan lv 98.5%。5ci chong fu shi yong shi yan biao ming ,cui hua ji ju you you liang de huo xing wen ding xing 。5que ding le ZnCa9(PO4)6F2cui hua ben an niao su chun jie zhi bei ben an ji jia suan jia zhi (Methyl N-phenyl carbamate,MPC)de gong yi tiao jian dui huo xing de ying xiang guan ji ,huo de le zui jia de gong yi tiao jian wei :180℃,6h,ben an 20 mmol,niao su yu ben an ma er bi wei 5:1,jia chun yu ben an ma er bi wei 2:1,cui hua ji 8.0 mmolzai ci tiao jian xia ,ben an zhuai hua lv 94.4%,ben an ji jia suan jia zhi shua ze xing 75.8%。ben lun wen de yan jiu jie guo dui FAPsuan jian zhong xin diao kong zhi bei ji cui hua ying yong ju you jiao hao de xue shu ji gong ye ying yong can kao jia zhi ,ta zhan le huan bao cui hua ji fu lin hui dan de ying yong ling yu 。
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论文作者分别是来自长春工业大学的王巍,发表于刊物长春工业大学2019-09-04论文,是一篇关于羟基磷灰石论文,氟磷灰石论文,模板法论文,共沉淀法论文,酸碱催化剂论文,尿素醇解论文,长春工业大学2019-09-04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,资料来自长春工业大学2019-09-04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:羟基磷灰石论文; 氟磷灰石论文; 模板法论文; 共沉淀法论文; 酸碱催化剂论文; 尿素醇解论文; 长春工业大学2019-09-04论文;