Structure,texture and surface acidity studies of a series of mixed zinc–aluminum (60–90 molar % Al) phosphate catalysts

A series of mixed zinc–aluminum phosphate (ZnAlP) catalysts containing 40–90 aluminum molar % were synthesized by a coprecipitation method and characterized by nitrogen adsorption–desorption, X‐ray diffraction, FTIR spectroscopy, thermogravimetric analysis (TGA), differential thermal analysis (DTA), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and temperature programmed desorption (TPD) of ammonia. The presence of aluminum greatly affected the surface properties of Zn₃(PO₄)₂ by delaying the crystallization process of Zn₃(PO₄)₂. All amorphous samples were shown to be mesoporous and they contained two types of aluminum surface hydroxyl groups and one type of phosphorus hydroxyl group, as shown by DRIFT spectra. The specific surface area and the acidity of ZnAlP increased on increasing the aluminum content. On the other hand, a great difference in the texture and the concentration of surface acid sites was found by changing the precipitating agent and calcination temperature. Thus these factors also play an important role in the final properties of these catalysts. © 2001 Society of Chemical Industry     

Brønsted acidity study of fiberglass materials by H/D-exchange

The kinetics of hydrogen isotopic exchange over fiberglass materials and reference samples (SiO₂, H₃PO₄/SiO₂, and HZSM-5) was studied at 500 °C under the dynamic adsorption–desorption equilibrium. The concentrations and H/D-exchange rates of different Brønsted acid sites (BAS) were determined using the numerical modeling of isotope exchange dynamics. The correlation between H/D-exchange rate of reference samples and their acidity determined by FTIR spectroscopy of adsorbed CO was established. Based on this correlation, the strength of BAS in fiberglass materials was shown to be comparable to that of HZSM-5 zeolite.     

测定SF_6气体酸度和SO_2含量的检测管的研制

介绍了可快速测定SF_6气体酸度和SO_2的检测管的研制结果。该检测管操作简单,使用方便,适宜于现场使用。     

Evaluating and quantifying the liming potential of phosphate rocks

The liming potential of phosphate rock was evaluated with theoreticalcalculations and quantified by laboratory titration and soil incubation. Threeanions present in the carbonate apatite structure of phosphate rock that canconsume protons and cause an increase in pH when dissolved from apatite arePO₄ ^3–, CO₃ ^2–, andF^–. The pKa for HF is so low that F^– has verylittle effect on increasing pH. The pKa for 2 protons onH₂PO₄ ^– and H₂CO₃are sufficiently high enough to cause an increase in pH withPO₄ ^3– and CO₃ ^2–releasedinto solution if the pH range is between 4 and 6. Because of the greater molarquantity of PO₄ ^3– compared toCO₃ ^2–, PO₄ ^3– exerts agreater affect on the liming potential of P rock. For a variety of phosphaterocks with a axes ranging from 9.322 to 9.374 Å in the carbonate apatitestructure, the theoretical % calcium carbonate equivalence (CCE) rangesfrom 59.5 to 62%. With the presence of gangue carbonate minerals from2.5to 10% on a weight basis in the phosphate rocks, the theoretical%CCE ranges from 59.5 to 63.1%. Use of AOAC method 955.01 forquantifying the %CCE of North Carolina phosphate rock (NCPR) and Idahophosphate rock (IDPR) resulted in %CCE ranging from 39.9 to 53.7%which were less than the theoretical values. The lower values measured in theAOAC method was presumed to be due to formation of CaHPO₄ orCaHPO₄·2H₂O precipitates which would result inlessthan 2 protons neutralized per mole of PO₄ ^3–released from carbonate apatite. The highly concentrated solution formed in themethod was considered not indicative of a soil solution and thus determined%CCE values would be suspect. A soil incubation study was conducted todetermine a more appropriate %CCE value in a soil environment usingCopper Basin, Tennessee soil with a soil pH of 4.2. Agricultural limestone,NCPR, IDPR, and a granulated IDPR were added to 100 g of soil atrates of 0.1, 0.3, 1, 3, and 10 g/kg soil, incubated for 105 daysat field moisture capacity, and analyzed for changes in soil pH and P. The%CCE of each phosphate rock addition was determined using limestone as astandard curve. The relationship between %CCE and % dissolved Pfollowed a quadratic model where%CCE=8.47+0.0078(%dissolved P)² (r²=0.84).At 0% dissolved P, the model predicted 8.47% CCE which wasprobably due to gangue carbonate minerals. The experimental model showedqualitative agreement with theory showing increased liming ability withincreased dissolved P from the P rock. However, the model showed lower%CCE than theoretical calculations when %P dissolved ranged from20 to 60%.     

Mo－Ni／HM催化剂的研究

研制应用于正戊烷异构化的非贵金属催化剂Ｍｏ－Ｎｉ０／ＨＭ。以丝光沸石作载体，经两次２ｍｏｌ／Ｌ的ＮＨ４ＮＯ３铵交换，一次质量分数为０．３６的乙酸交换；用常规方法在室温下先后浸渍活性组分Ｍｏ，助催化剂组分Ｎｉ，ｗ（Ｍｏ）与ｗ（Ｎｉ）的最佳配比为３．２％：１．０％，焙烧温度为４７５℃。在临氢高压微反－色谱联合装置上对该催化剂进行考察，工艺条件为：反应温度３４０℃，压力３．０ＭＰａ，空速１．０ｈ－１，氢油摩尔比４：１。结果为：异戊烷收率达到５５．２％，≥Ｃ５液体收率为９５．２％。研究表明，此催化剂具有活性高，选择性好，成本低等特点，异构化性能优于只用两次铵交换、不同焙烧温度的其它催化剂。     

Mo－Ni／HM催化剂的研究

研制应用于正戊烷异构化的非贵金属催化剂Ｍｏ－Ｎｉ０／ＨＭ。以丝光沸石作载体，经两次２ｍｏｌ／Ｌ的ＮＨ４ＮＯ３铵交换，一次质量分数为０．３６的乙酸交换；用常规方法在室温下先后浸渍活性组分Ｍｏ，助催化剂组分Ｎｉ，ｗ（Ｍｏ）与ｗ（Ｎｉ）的最佳配比为３．２％：１．０％，焙烧温度为４７５℃。在临氢高压微反－色谱联合装置上对该催化剂进行考察，工艺条件为：反应温度３４０℃，压力３．０ＭＰａ，空速１．０ｈ－１，氢油摩尔比４：１。结果为：异戊烷收率达到５５．２％，≥Ｃ５液体收率为９５．２％。研究表明，此催化剂具有活性高，选择性好，成本低等特点，异构化性能优于只用两次铵交换、不同焙烧温度的其它催化剂。     

添加丢糟生产大曲的试验报告

通过１吨规模的生产试验，阐明在常规小麦制大曲原料中添加一定比例的丢糟，不仅使丢糟得到利用，而且还起到促进曲霉菌生长及抑制产酸杂菌的作用     

Characterization of γ-alumina doped with Li and K by infrared studies of CO adsorption and27Al-NMR

The influence of alkali metals on the Lewis acid sites of gamma-alumina has been studied with NMR and IR of adsorbed CO. The physical properties of the alumina are slightly changed by the addition of low alkali metal concentrations. Li and K are adsorbed selectively on tetrahedral Lewis Al³⁺ sites of the alumina surface. These effects on the tetrahedral cations are more marked with increasing molar concentration and ionic radius of the alkali metal added to alumina. Results demonstrate that the influence of the alkali metals is not only due to steric factors but also to possible electronic modifications.This work was supported by a grant from CONICET, Argentina.     

功能化的酸性离子液体

围绕着功能化酸性离子液体这一主题,对新型Lewis,Bronsted酸性离子液体、离子液体的酸性测定以及酸性离子液体在异丁烷/丁烯烷基化反应中的应用进行了介绍和评述;提出了由新型酸性离子液体的合成、其酸性的表征及其催化性能的评价3方面有机地构成了研发酸性离子液体参与的工艺技术的良性过程;明确了“功能化”的涵义;展望了酸性离子液体巨大的工业应用前景。