Synthesis of SAPO-41 from a new reproducible route using H3PO3 as the phosphorus source and its application in hydroisomerization of n-decane

In the new reproducible route, phosphorous acid (H₃PO₃) or the mixture of H₃PO₃ and phosphoric acid (H₃PO₄) are used as the phosphorus source to synthesize microporous silicoaluminophosohates. It is found that gels containing H₃PO₃ favor the formation of SAPO-41 materials. With only H₃PO₃ as the phosphorus source, pure SAPO-41 phase can be prepared with high crystallinity. When the mixture of H₃PO₃ and H₃PO₄ is used as the phosphorus source, the crystallization of SAPO-41 can be accelerated. Raman and XRD results show that SAPO-41 can be formed after crystallizing for 12 h. The dosage of the template di-n-propylamine (DPA) can be reduced in the mixed phosphorus source system. The SAPO-41 has been used to prepare catalysts for the hydroisomerization of n-decane. High selectivity of isomerization (89.5%) has been observed even at high conversion (88%) over the Pt/SAPO-41.     

高酸度条件下单波长、双峰双波长分光光度法测定铬(Ⅵ)

铬(Ⅵ)的测定,在金属材料的分析中具有重要意义。目前,铬的测定仍采用二苯卡巴肼法,该法的灵敏度虽较高(ε=34600),但由于显色剂的稳定性很差,显色剂溶液和工作曲线需当天配制和绘制,除给操作带来许多麻烦外,还造成大量试剂的浪费。     

电感耦合等离子体发射光谱法测定钒钛铁矿中二氧化钛

传统的分光光度法或滴定法测定矿石中二氧化钛,操作繁琐,周期长,且分析效率低,不适合大批量样品的快速分析. 采用氢氟酸、盐酸、硝酸、高氯酸混合酸和1 mL 1+1硫酸溶解试样,用10%的盐酸进行提取,再以电感耦合等离子发射光谱直接测定二氧化钛含量. 试验结果表明,在波长336.1 nm处,钒钛磁铁矿国家标准物质的测定值与标准值基本一致. 方法确定在波长336.1 nm处进行实验,二氧化钛的检出限为30 μg/g,精密度(RSD,n=12)小于0.8%. 方法操作简单,数据准确可靠,适合批量钒钛     

Ag/Ag_3PO_4/g-C_3N_4复合光催化剂的合成与再生及其可见光下的光催化性能(英文)

研究了用离子交换沉淀法制备的Ag/Ag3PO4/g-C3N4的可见光光催化性能及再生方法.通过X射线衍射(XRD)、场发射扫描电子显微镜(FESEM)、紫外-可见(UV-Vis)吸收光谱及X射线光电子能谱(XPS)对其进行了结构特性分析.XRD结果显示再生后催化剂的结构未发生改变.FESEM及UV-Vis分析结果说明催化剂由Ag3PO4与g-C3N4复合而成.XPS分析结果表明催化剂表面出现少量的银单质.利用可见光(λ420nm)照射下的苯酚降解实验评价了样品的光催化活性,并通过活性物种及能带结构的分析对催化剂的光催化机理进行了推测.研究表明,Ag/Ag3PO4/g-C3N4的光催化活性明显高于纯Ag3PO4及纯g-C3N4,主要原因归结为单质银、Ag3PO4及g-C3N4的协同效应.经过氧化氢和磷酸氢铵钠(NaNH4HPO4)的再生可完全恢复催化剂的活性,这表明该绿色环保的再生方法可实现Ag/Ag3PO4/g-C3N4催化剂在环境中的实际应用.     

Introduction of H2SO4 and H3PO4 into Crystalline Porous Organic Salts(CPOS-1) for Outstanding Proton Conductivity

To improve the proton conduction of crystalline porous organic salts(CPOS-1), H₂SO₄ and H₃PO₄ were introduced into the channel to obtain H₂SO₄@CPOS-1 and H₃PO₄@CPOS-1. Compared to CPOS-1, the proton conductivities of H₂SO₄@CPOS-1 and H₃PO₄@CPOS-1 increased two orders of magnitude and one order of magnitude at 303 K and 100% RH, respectively. It can be attributed to the increasing concentration of the protons, which dissociates from the acids.     

酸性离子液体萃取/催化二苯并噻吩氧化脱硫反应的优化

ö以Brönsted酸性离子液体N-甲基-2-吡咯烷酮磷酸二氢盐(\[Hnmp\]H₂PO₄)为萃取剂和催化剂,双氧水为氧化剂,二苯并噻吩(DBT)溶于正辛烷为模型油,利用正交实验法优化了DBT氧化脱硫反应工艺。所优化的反应条件为：反应温度60℃,模型油与离子液体体积比为1∶1,氧/硫摩尔比为16, 氧化时间5h;在此条件下模型油脱硫率达99.8%,实际柴油脱硫率为64.3%。由正交实验极差可知,各因素对DBT脱硫率影响的大小依次为：反应温度＞反应时间＞氧/硫摩尔比＞剂油比;离子液体循环利用6次,脱硫率下降不明显。     

Pitzer方程应用于离子液体[Cnmim][H2PO4](n= 3, 4, 5, 6)溶解焓研究

在298.15 K下,利用等温环境溶解反应热量计,测定了离子液体[C_nmim][H₂PO₄] (n= 3, 4, 5, 6) (1-烷基-3-甲基咪唑磷酸盐)在水中不同浓度的摩尔溶解热(Δ_solH_m),根据Pitzer电解质溶液理论计算得到了标准摩尔溶解焓(Δ_solH_m⁰)和Pitzer焓参数：β_MX^(0)L, β_MX^(1)L,和C^ϕL,并计算了表观相对摩尔焓。通过推导讨论,得到了离子液体[C_nmim][H₂PO₄](n= 3, 4, 5, 6)同系物每摩尔亚甲基对标准摩尔溶解焓的贡献。     

多卤代变色酸双偶氮类稀土显色剂的合成及分子结构与吸光性能的关系

本文设计、合成了一类新型稀土显色剂--多卤代变色酸双偶氮衍生物,它们易溶于水、乙醇和丙酮,不溶于苯、己醚和氯仿,是具有高灵敏度、高选择性、显色酸度高、空白值低的优良稀土显色剂,本文还研究了试剂的分子结构和吸光性能的关系,当助色基及其取代位置一定时,具有-AsO₃H₂、-COOH、-PO_3H、-Cl络合功能基的性质,其灵敏度较高。     

One Dimensional Iron Molybdophosphate Anionic Chains with Different Structural Arrangements Reflecting a Flexibility Character

Structural comparison of a new compound[(bpp)₃H₆]Fe₂^IIIFe₂^IIMo₂₄^V(H₂PO₄)₈(HPO₄)₄(PO₄)₄O₄₈(OH)₁₂· (H₂O)₄·2H₂O(1)[bpp=1,3-di(4-pyridyl)propane] with our previously reported two compounds[(bpy)₃Fe^II]₃· Fe₂^IIIFe₂^IIMo₂₄^V(H₂PO₄)₈(HPO₄)₄(PO₄)₄O₄₈(OH)₁₂(H₂O)₄·12H₂O(2) and[(bpy)₃Fe^II]₂Fe^IIFe^IIIMo₁₂^V(H₂PO₄)₂(H_2-xPO₄)·(H_1+xPO₄)(HPO₄)₂(PO₄)₂O₂₄(OH)₆(H₂O)₂·9H₂O(x=0―1)(3)(bpy=2,2'-bipyridine), which all exhibit one-dimensional mixed-valence iron molybdophosphate anionic chains constructed by alternating connection of Fe^III ions and magic[Fe^II(Mo₆P₄O₃₁)₂] units, reveals that the non-hydrogen atomic ratios of Mo:Fe:P:O within the polymeric anionic chains are the same for all the three compounds, while the polymeric anionic chains of the different compounds bear different numbers of negative charges. And therefore there exist different numbers of counter cations per {Fe₂^III[Fe₂^II(P₁₆Mo₂₄^VO₁₂₄)]} unit found in the titled compounds. It discloses that not only are the spatial assembling of counter cations and polymeric inorganic chains of three compounds quite different, but also the O―Fe^III―O bond angles and Fe^III―O bond lengths of the three different inorganic chains exhibit small differences. What is more important is that such small changes in bond length and bond angle in the assemblage of Fe^III―O bonds lead to the considerable fluctuations of inorganic chains in their structural conformation within the three compounds, reflecting an interesting phenomenon of “flexibility" in the pure inorganic one dimensional mixed-valence iron molybdophosphate chains.     

伯胺N1923萃取磷酸的研究

研究了N₁₉₂₃萃取磷酸的性能,考察了溶剂和温度对萃取平衡的影响,用斜率法、饱和法以及红外光谱、核磁共振谱确定了不同条件下萃合物的组成。     

Preparation and Conducting Behavior of Amphibious Organic/Inorganic Hybrid Proton Exchange Membranes Based on Benzyltetrazole

A series of novel amphibious organic/inorganic hybrid proton exchange membranes with H3PO4 doped which could be used under both wet and dry conditions was prepared through a sol-gel process based on ac...     

氧化铝纳米线的制备及其形成机理

采用二次铝阳极氧化技术, 制备高度有序的铝阳极氧化膜(AAO模板). 经X射线衍射(XRD)分析, 模板为无定形结构. 将模板放入腐蚀液中, 可获得大量无定形结构的氧化铝纳米线. 模板在800 ℃下退火4 h后, 变为γ-Al2O3结构, 采用类似腐蚀液溶解模板, 得到大量γ-Al₂O₃纳米线. 研究了腐蚀液种类、腐蚀时间和模板晶体结构等因素对生成氧化铝纳米线的影响, 并利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)和XRD对纳米线的形貌与结构进行了表征. 结果表明, 在多种腐蚀液中, 均可获得氧化铝纳米线; 随着腐蚀时间的增加, 纳米线的长度增加, 直径变小, 长径比增大; 氧化铝纳米线的晶体结构与所采用模板的晶体结构一致. 此外, 还采用原子力显微镜(AFM)和SEM对AAO膜的表面形貌及其结构特点进行了详细的观测, 并以此为基础讨论了氧化铝纳米线的形成机理, 认为AAO模板本身存在的花状微结构是形成纳米线的内因, 花瓣间的凹陷部位首先被腐蚀断裂, 形成氧化铝纳米线.     

Hydrolysis and polycondensation of ethyl silicates. 1. Effect of pH and catalyst on the hydrolysis and polycondensation of tetraethoxysilane (TEOS)

The effect of pH and of catalysts on the course of the hydrolysis and condensation of tetraethoxysilane (TEOS) in water—ethanol solution was studied with the aid of chromatography, potentiometry and gelation tests. Strong acids (HCl, HClO₄, HNO₃, H₂SO₄, p-toluenesulphonic acid), weak acids (Cl₃CCOOH, (COOH)₂, ClCH₂COOH, CH₃COOH, HCOOH) and LiOH were used as catalysts. The rate of hydrolysis depended on the pH of the solution and not on the chemical structure of the catalyst. The hydrolysis was both acid and base catalysed and its rate was at a minimum at pH 7.0.

The rate of condensation of the reaction products of the hydrolysis of TEOS (water—ethanol solutions of ethoxyhydroxysiloxanes) was at a minimum at a pH of about 2.0. The condensation was both acid and base catalysed and was markedly accelerated by both HF and H₃PO₄.     

钠和钾离子对磷酸二氢根拉曼光谱的影响

磷酸二氢根(H₂PO^-₄)溶液在生物缓冲、分子识别、晶体生长等方面有着重要的研究价值。 本文以KH₂PO₄(KDP)和NaH₂PO₄(NaDP)溶液为研究对象,利用原位微区拉曼光谱研究钠离子和钾离子对H₂PO^-₄溶液团簇聚合及化学键振动的影响,讨论单价阳离子(K⁺,Na⁺)的差异、溶液浓度对H₂PO^-₄拉曼位移变化和成核诱导时间的影响。 结果表明,拉曼位移变化、成核诱导时间随阳离子溶液电负性的增加、浓度的降低而增大。 在拉曼光谱中观察到P(OH)₂和PO₂振动峰在成核过程中发生偏移,表明由氢键作用导致的团簇构型逐渐稳定,化学键逐渐增强,深化溶液结晶过程中对溶液结构和化学键的理解。     

Optimization of zinc phosphate coating on 7075-T6 aluminum alloy

A zinc phosphate coating process on 7075-T6 aluminum alloy has been significantly improved through a combined approach of titanium colloid pretreatment, pH level adjustment, fluoride additive and ZnO/H₃PO₄ ratio adjustment. In particular, optimum phosphate coatings were formed in coating baths with a ZnO/H₃PO₄ ratio of 0.205 and 0.256. Coating morphology studied by SEM reveals that the adjustment in the coating procedure produces an improved crystalline coating layer with high coverage and small grain size. For coatings formed in a bath with a ratio of 0.205, the coverage of the crystalline patches on top of the amorphous coating base is almost complete. The chemical composition of the coating layers has been characterized by XPS and SIMS. The crystalline and amorphous coating phases formed in the bath with a ratio of 0.205 were found to have compositions given schematically as Zn_x(PO₄) and Zn_xAl_y(PO₄), respectively. In contrast, neither coating phase formed in the bath with a ratio of 0.256 shows the presence of Al.     

A Novel Layered Complex with Rhomboidal Channels： Hydrothermal Synthesis, Crystal Structure, and Properties of Cu （4,4′-bipy）2（H2PO4）2（H2O）2（bipy=bipyridine）

The combination of both 4,4′-bipyridine(4,4′-bipy) and dihydrogen phosphate anion ligands with copper(Ⅱ) results in the formation of a novel layered compound Cu(4,4′-bipy)₂(H₂PO₄)₂(H₂O)₂. The crystal structure comprises discrete neutral Cu(4,4′-bipy)₂(H₂PO₄)₂(H₂O)₂ units. The copper atom, located on the crystallographic twofold axis, is coordinated with two nitrogen atoms of terminal 4,4′-bipy ligands and two water molecules at the equatorial positions, and two dihydrogen phosphate oxygen atoms at the axial positions, forming an elongated octahedron. The complex is a two-dimensional distorted rhomboidal network possessing two kinds of rhomboids with dimensions of ca. 1.6792 nm×0.3203 nm and 1.2778 nm×0.3198 nm, respectively. The two-dimensional networks are stacked parallelly on each other along c-axis to give an extended three-dimensional channel network with an interlayer distance of ca. 0.5030 nm. Crystal data: triclinic, space group P1, a=1.0253(2) nm, b=1.4501(3) nm, c=0.79715(16) nm, α=97.91(3)°, β=90.99(3)°, γ=85.54(3)°, V=1.1703(4) nm³, Z=2, R=0.0892, wR=0.2451.     

垃圾衍生燃料热解半焦气化过程中HCl与H2S析出规律

通过水平管式气化炉和化学吸收法,对比研究了矿化垃圾热解半焦（ARC）和常规垃圾热解半焦（NRC）在水蒸气和CO₂气化过程中腐蚀性气体（HCl和H₂S）的析出特性,考察了气化温度、气化介质类型和流量对腐蚀性气体析出特性的影响。当气化温度升至950℃,ARC在水蒸气气化过程中的碳气化率、HCl和H₂S产率分别为66.1%、100%和74.9%,而其在CO₂气化过程中的碳气化率、HCl和H₂S产率分别为77.8%、100%和2.9%;NRC在水蒸气气化过程中的碳气化率、HCl和H₂S产率分别为98.8%、100%和53.7%,而其在CO₂气化过程中的碳气化率、HCl和H₂S产率分别为100%、96.2%和10.3%。以NRC为原料,考察了水蒸气和CO₂流量对其HCl和CO₂析出特性的影响。NRC的HCl和H₂S产率均随水蒸气流量增加而增加,但当水碳比大于等于3.3时,其促进作用不再明显。NRC的HCl产率随CO₂流量的增加而增加,而H₂S产率随CO₂流量的增加而减小。     

Catalytic effects of eight inorganic additives on pyrolysis of pine wood sawdust by microwave heating

In this paper, pyrolysis of pine wood sawdust was carried out by microwave heating at ca. 470 °C under dynamic nitrogen atmosphere. Eight inorganic additives (NaOH, Na₂CO₃, Na₂SiO₃, NaCl, TiO₂, HZSM-5, H₃PO₄, Fe₂(SO₄)₃) were investigated in terms of their catalytic effects on the pyrolysis. All of the eight additives have increased yields of solid products greatly and decreased yields of gaseous products more or less. Yields of liquid products have not subjected to dramatic change. The incondensable gases produced from pyrolysis consist mainly of H₂, CH₄, CO and CO₂. All of the eight additives have made these gases evolve earlier, among which the four sodium additives have the most marked effect. All the additives have made the amount of CH₄ and CO₂ decrease, while all of them except NaCl, TiO₂ and Fe₂(SO₄)₃ have made that of H₂ increase and all of them except Na₂SiO₃ and HZSM-5 have made that of CO decrease. Alkaline sodium compounds NaOH, Na₂CO₃ and Na₂SiO₃ favor H₂ formation most. The most abundant organic component in the liquid products from pyrolysis of untreated sample and samples treated by all the additives except H₃PO₄ and Fe₂(SO₄)₃ is acetol. All the four sodium compounds favor acetol formation reaction and the selection increasing effect follows the order of NaOH > Na₂CO₃ ≈ Na₂SiO₃ > NaCl. TiO₂ goes against the formation of acetol, HZSM-5 has no marked effect on acetol formation. The two dominant organic components identified in the liquid products from pyrolysis of H₃PO₄ and Fe₂(SO₄)₃ treated samples are both fufural and 4-methyl-2-methoxy-phenol. A possible pathway for acetol formation is tentatively proposed.     

无机盐活化剂-氨基酸盐基溶液捕集温室气体CO2

将无机盐K₃PO₄、K₂HPO₄和KH₂PO₄作为活化剂,分别添加于氨基乙酸盐溶液中,形成CO₂活化吸收剂,采用膜接触器 再生循环装置,评价和比较了氨基乙酸盐和活化吸收剂捕集CO₂的性能,研究了活化剂的浓度、气液流速等因素对总体积传质系数、传质通量和捕集率的影响。结果表明,磷酸盐活化剂在氨基乙酸盐吸收剂中,对CO₂的捕集均产生影响,活化效应存在PO₄^3－＞HPO₄^2－＞H₂PO₄^－的规律;添加少量活化剂的作用比添加较多量的活化作用大;活化吸收剂的捕集率明显大于非活化吸收剂;膜吸收流体力学状态的改变,能够改善膜接触器传质性能,增大传质通量,但增大的程度有限。     

Stepwise Fabrication of Proton-conducting Covalent Organic Frameworks for Hydrogen Fuel Cell Applications

Exploring new materials to manufacture proton-conducting membranes(PEMs) for fuel cells is highly significant. In this work, we fabricated two robust and highly crystalline porous covalent organic frameworks(COFs) via a stepwise synthesis strategy. The synthesized COF structures are integrated into high-density azo and amino groups, which allow to anchor acids for accelerating proton conduction. Moreover, the COFs exhibit good chemical stability and high hydrophilicity. These features make them potential platforms for proton conduction applications. Upon loaded with H₃PO₄, the COFs(H₃PO₄@COFs) deliver a high proton conductivity of 3.15×10^‒2 S/cm at 353 K under 95% relative humidity(RH). Furthermore, membrane electrode assemblies are fabricated using H₃PO₄@COF-26 as the solid electrolyte for a single fuel cell outputting a maximum power density of 18 mW/cm².