艾迪奥特曼
石油学报(石油加工)ACTA PETROLEI SINICA(PETROLEUM PROCESSING SECTION)2004 Vol.20 No.1 P.12-21--------------------------------------------------------------------------------EFFECT OF STEAM TREATMENT AND PHOSPHOROUS ACID MODIFICATION OF HZSM-5 ON ITS PHYSICOCHEMICAL AND CATALYTIC PROPERTIESAbstract:Physicochemical and catalytic properties of phosphorous acid modified HZSM�5 ze olites treated with 100% steam at 673,873,and 1073*!K have been investigated.T he structure of the samples was characterized by XRD.The acidity and distributio n of the acidic sites were studied by IR using pyridine as probe molecule and te mperature programmed desorption (TPD) of ammonia.The state of phosph orus were studied by XPS,showing that P (Ⅲ) was oxidized to P (Ⅴ),a model for the surface structure of the modification is proposed.Th e textural properties of catalysts determined by nitrogen isothermal adsorption �desorption measurements suggest the isothermal type of all samples is a combin ation of type Ⅰ and type Ⅳ,all hysteresis loops resemble the H4�type in the IUPAC classification.The state of aluminum was characterized by 27 Al MAS N MR spectroscopy.AM1 (Austin model) semi�empirical method and cluster model method have been employed to study the stability of two possible phosphor us modified zeolite geometries,the difference was the bridging oxygen of phosph orus coordination with aluminum or the terminal oxygen of phosphorus coordinatio n with aluminum.The result showed that the terminal oxygen coordination was more possible according to the heat of formation (HF).The �n��heptane cracking reaction was selected as probe reaction to investigate the activity of studied samples.�Keywords:HZSM�5 zeolites;steam treatment;phosphorous acid modificati on;texture;cracking activity 亚磷酸和水蒸气联合改性的HZSM-5的物化性质和催化性能研究吕仁庆 唐博 王震宇 王秋英 项寿鹤 摘 要:考察了由亚磷酸改性的HZSM-5在673、873和1073K温度下100%水蒸气处理样品的物化和催化性质.采用XRD表征了样品的结构.通过吸附吡啶红外光谱和NH3-TPD进行了酸性和酸分布研究.XPS的研究结果表明,P由+3价氧化成了+5价,并提出了可能的改性的表面结构模型.通过N2吸附-脱附等温线研究了样品的孔结构,样品的吸附-脱附等温线为Ⅰ型和Ⅳ型的复合型,滞后环为IUPAC分类的H4型.Al的状态由27Al MAS NMS表征.采用AM1(Austin Model Ⅰ)半经验量子化学方法和模型簇法筛选了磷改性可能的两种结构模型,其区别在于磷上的桥氧与铝配位还是端氧与铝配位,结果表明端氧与铝配位的可能性更大.以正庚烷裂化反应为探针反应考察了样品的活性.关键词:HZSM-5沸石;水热处理;亚磷酸改性;结构;裂化活性CLC Number:TE624.4 Document ID:AArticle ID:1001-8719(2004)01-0012-10 Foundation Item:国家自然科学基金(20233030)和石油大学中国石油天然气集团公司催化重点实验室资助项目Author Resume:吕仁庆(1969-),男,讲师,博士研究生,从事沸石催化研究;唐博(1964-),男,高级工程师,博士研究生,从事工业催化研究;王震宇(1974-),男,工程师,硕士,从事催化剂生产工作;王秋英(1964-),女,高级工程师,硕士,从事沸石催化研究:项寿鹤(1939-),男,教授,从事沸石合成与催化研究. 通讯联系人:吕仁庆 Author Unit:吕仁庆(南开大学,化学系,天津,300071) 唐博(南开大学,化学系,天津,300071) 王震宇(南开大学,催化剂厂,天津,300071) 王秋英(南开大学,催化剂厂,天津,300071) 项寿鹤(南开大学,化学系,天津,300071) References:〔1〕Scherzer J.Octane-enhancing,zeolitic FCC catalysts,scientific and technical aspects[J].Catal Rev-Sci Eng,1989,31(3):215-354.〔2〕Lischke G,Eckelt R,Jerschkewitz H-G,et 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acidity[J].Microporous Mesoporous Materials,1998,20:363-369.〔17〕Rahman A,Lemay G,Adnot A,et al.Spectroscopic and catalytic study of P-modified ZSM-5[J].J Catal,1988,112(2):453-463.〔18〕Rahman A,Adnot A,Lemay G,et al.Chemical modification of H-ZSM-5 by adsorption of rhodium and phosphorus complexes[J].Appl Catal,1989,50:131-147.〔19〕Seo G,Ryoo R.31P,27Al and 129Xe NMR study of phosphorus-impregnated HZSM-5 zeolite catalysts[J].J Catal,1990,124:224-230.〔20〕Suzuki K,Kiyozumi Y,Matsuzaki K.Effect of modification of ZSM-5 type zeolite with calcium phosphate on its physico-chemical and catalytic properties[J].Appl Catal,1988,39:315-324.〔21〕Ikai S,Okamoto M,Nishioka H,et al.HZSM-5 pelletized and modified with α-Ca3(PO4)2 and HPO�42- as a catalyst for methanol conversion[J].Appl Catal,1989,49:143,163.〔22〕Shen Y F,Ko A N,Grange P.Study of phosphorus-modified aluminum pillared montmorillonite I Effect of the nature of phosphorus compounds[J].Appl Catal,1990,67:93-106.〔23〕Wu E L,Lawton S L,Olson D H,et al.ZSM-5-type material,factors affecting crystal symmetry[J].J Phys Chem,1979,83(21):2777-2781.〔24〕Mastikhin V M,Zamaraev K I.Studies of heterogeneous catalysis using high-resolution solid state NMR[J].Applied Magnetic Resonance,1990,1:295-350.〔25〕Lü R Q,Wang Q Y,Tang B,et al.Physicochemical characterization and catalytic study of steam combined with phosphorus modified HZSM-5[C].ZMPC2003 Symposium,August 3-6 in Sapporo,Japan,submitted.〔26〕Lischke G,Eckelt R,Jerschkewitz H-G,et al.Spectroscopic and physicochemical characterization of P-modified H-ZSM-5[J].J Catal,1991,132(1):229-243.〔27〕Wagner C D,Riggs W M,Davis L E,et al.Handbook of X-ray photoelectron spectroscopy,A reference book of standard data for use in X-ray photoelectron spectroscopy[M].Published by Perkin-Elmer Corporatio n physical electronics Division 6509 Flying Cloud drive Eden Prairie,Minnesota 55344.〔28〕Dewar M J S,Zoebisch E G,Healy E F S.AM1: A new general purpose quantum mechanical molecular model[J].J Am Chem Soc,1985,107:3902-3909.Manuscript Received:2003年1月13日Published:2004年2月25日

MIssinGLess
磷。
第15号化学元素,符号P。处于元素周期表的第三周期、第ⅤA族。磷存在于人体所有细胞中,是维持骨骼和牙齿的必要物质,几乎参与所有生理上的化学反应。
磷还是使心脏有规律地跳动、维持肾脏正常机能和传达神经刺激的重要物质。没有磷时,烟酸(又称为维生素B3)不能被吸收;磷的正常机能需要维生素D(维生素食品)和钙(钙食品)来维持。
磷被首次发现存在于恒星爆炸后的宇宙残余物里。对超新星残余物仙后座A的最新观测揭示了磷存在的最新证据。它是在深空发现的两大元素之一,或可能给科学家提供有关生命在宇宙里的可能性的线索。
关于磷元素的发现,还得从欧洲中世纪的炼金术说起。那时候,盛行着炼金术,据说只要找到一种聪明人的石头──哲人石,便可以点石成金,让普通的铅、铁变成贵重的黄金。
炼金术家仿佛疯子一般,采用稀奇古怪的器皿和物质,在幽暗的小屋里,口中念着咒语,在炉火里炼,在大缸中搅,朝思暮想寻觅点石成金的哲人石。
1669年,德国汉堡一位叫布朗特(Brand H)的商人在强热蒸发人尿的过程中,他没有制得黄金,却意外地得到一种像白蜡一样的物质,在黑暗的小屋里闪闪发光。这从未见过的白蜡模样的东西,虽不是布朗特梦寐以求的黄金,可那神奇的蓝绿色的火光却令他兴奋得手舞足蹈。
他发现这种绿火不发热,不引燃其它物质,是一种冷光。于是,他就以“冷光”的意思命名这种新发现的物质为“磷”。磷的拉丁文名称Phosphorum就是“冷光”之意,它的化学符号是P,它的英文名称是Phosphorus。
参考资料:百度百科-磷
兴业腾达装饰
p是化学元素磷元素。
磷,原子序数15,原子量30.973762, 磷有白磷、红磷、黑磷三种同素异构体。白磷又叫黄磷为白色至黄色蜡性固体,熔点44.1°C,沸点280°C,密度1.82克/厘米3。
白磷活性很高,必须储存在水里,人吸入0.1克白磷就会中毒死亡。白磷在没有空气的条件下,加热到250°C或在光照下就会转变成红磷。
红磷无毒,加热到400°C以上才着火。在高压下,白磷可转变为黑磷,它具有层状网络结构,能导电,是磷的同素异形体中最稳定的。
扩展资料:
一、元素描述
单质磷有几种同素异形体。其中,白磷或黄磷是无色或淡黄色的透明结晶固体。密度1.82克/厘米3。熔点44.1℃,沸点280℃,着火点是40℃。放于暗处有磷光发出。有恶臭。剧毒。
白磷几乎不溶于水,易溶解与二硫化碳溶剂中.在高压下加热会变为黑磷,其密度2.70克/厘米3,略显金属性。电离能为10.486电子伏特。不溶于普通溶剂中。
白磷经放置或在400℃密闭加热数小时可转化为红磷。红磷是红棕色粉末,无毒,密度2.34克/厘米3,熔点59℃,沸点200℃,着火点240℃。不溶于水。
在自然界中,磷以磷酸盐的形式存在,是生命体的重要元素。存在于细胞、蛋白质、骨骼和牙齿中。在含磷化合物中,磷原子通过氧原子而和别的原子或基团相联结。
二、磷的发现
关于磷元素的发现,还得从欧洲中世纪的炼金术说起。那时候,盛行着炼金术,据说只要找到一种聪明人的石头──哲人石,便可以点石成金,让普通的铅、铁变成贵重的黄金。
炼金术家仿佛疯子一般,采用稀奇古怪的器皿和物质,在幽暗的小屋里,口中念着咒语,在炉火里炼,在大缸中搅,昭思慕想寻觅点石成金的哲人石。
1669年,德国汉堡一位叫布朗特(Brand H)的商人在强热蒸发人尿的过程中,他没有制得黄金,却意外地得到一种像白蜡一样的物质,在黑暗的小屋里闪闪发光。
这从未见过的白蜡模样的东西,虽不是布朗特梦寐以求的黄金,可那神奇的蓝绿色的火光却令他兴奋得手舞足蹈。他发现这种绿火不发热,不引燃其它物质,是一种冷光。
于是,他就以“冷光”的意思命名这种新发现的物质为“磷”。磷的拉丁文名称Phosphorum就是“冷光”之意,它的化学符号是P,它的英文名称是Phosphorus。
参考资料:
百度百科-磷元素
优质英语培训问答知识库