固体超强酸SO_4~(2-)/ZrO_2催化合成乙二醇乙醚醋酸酯

在固体超强酸SO42-/ZrO2催化下,以乙二醇单乙醚和冰醋酸为原料,合成了乙二醇乙醚醋酸酯。考察了催化剂用量、物料配比、反应时间、带水剂等因素对反应的影响。实验结果表明,固体超强酸SO42-/ZrO2对合成乙二醇乙醚醋酸酯有着良好的催化活性,在催化剂用量为反应物料总质量的2%,乙二醇单乙醚9.01 g,n(乙二醇单乙醚)∶n(冰醋酸)=1∶3,回流时间2.5 h,带水剂环己烷用量为17 mL的条件下产品收率达95.8%,且催化剂重复使用5次仍保持较高活性。产品经红外、气质进行定性分析,确定结构为乙二醇乙醚醋酸酯。     

ZrO2-SiO2二元系统平面光波导薄膜的制备与性能表征

应用溶胶-凝胶技术,以TEOS与ZrOCl2·8H2O为先驱体,研制了用于有源光波导基质材料的ZrO2-SiO2二元系统薄膜,探明了ZrO2-SiO2二元系统薄膜折射率、厚度与薄膜组分、匀胶速度、陈化时间、热处理温度的内在关系,实现薄膜厚度和薄膜折射率在一定范围内的连续可调,为研制一类新型的光通信窗口有源光波导材料提供了基质材料.     

仲丁醇脱氢催化剂性能

采用XRD、TPR、BET和N2O滴定法对仲丁醇脱氢催化剂YTDH-1G与对比剂A进行表征,并采用常压固定床反应器考察两种催化剂的仲丁醇脱氢活性和甲乙酮选择性。结果表明,催化剂中添加Zr O2后可以提高催化剂活性组分的分散度,改善催化剂的还原性能。催化剂YTDH-1G表明的Cu比表面积和分散度明显大于对比剂A。在考察的实验范围,催化剂YTDH-1G的催化活性和产物选择性优于对比剂A,对工艺条件的适应性较强,可在较宽的温度和空速范围使用,具有较好的工业应用前景。     

Au-Pd/ZrO2可见光下催化苯甲醇氧化反应条件探索

利用硼氢化钠还原法制备出Au-Pd/ZrO₂负载型双金属纳米催化剂,采用XRD、UV-vis DRS、TEM等手段对催化剂的结构、吸光能力、粒度、形貌等性能进行表征。结果显示,金、钯成功负载于二氧化锆上,且金、钯以球形颗粒均匀分散。可见光照射下,研究了Au-Pd/ZrO₂双金属纳米催化剂对苯甲醇氧化生产苯甲醛反应的适宜条件。实验结果显示,可见光照射下,反应时间为12 h、反应温度为（35±3） ℃、5.0 mL异丙醇为溶剂、50 mg Au-Pd（2:1）/ZrO₂为催化剂、1.0 mmol氢氧化钾为碱源的条件下,苯甲醇氧化生产苯甲醛产率最佳。     

Y2O3添加量对Al2O3/ZrO2复合材料烧结行为和热机械性能的影响

研究了Y2O3添加量对Al2O3/ZrO2复合材料烧结行为和热机械性能(高温抗折强度和抗热震性)的影响,并研究了这些性能与物相组成和显微结构间的关系.结果表明:Y2O3在Al2O3/ZrO2复合材料中起稳定ZrO2晶型、改善烧结致密化、提高高温抗折强度和抗热震性的作用.当Y2O3添加量为1%时,试样的烧结性能和高温抗折强度较佳,体积密度、显气孔率和线收缩率分别为3.27 g/cm3、21.95%和7.43%,高温抗折强度达29 MPa;抗热震性则在Y2O3添加量为0.5%时较佳,其残余强度保持率为71%.Y2O3对Al2O3/ZrO2复合材料烧结性能和热机械性能的影响与Y2O3/ZrO2固溶体的形成、Al2O3和ZrO2晶体间的结合程度及试样中微裂纹含量密切相关.     

Dispersion and properties of zirconia suspensions for stereolithography

Stereolithography is an attractive technique for the fabrication of complex-shaped ceramic components with high dimensional accuracy. One of the challenges in this technology is the development of high solid loading, low viscosity photosensitive ceramic suspension. In this study, the dispersion of zirconia in photocurable resin and the slurry properties were intensively investigated. Rheological measurements showed that DISPERBYK-103 proved to be an effective dispersant. 42 vol% ZrO₂ suspension was successfully prepared using 3.5 wt% DISPERBYK-103 as the dispersant, with a suitable viscosity (4.88 Pa·s) below the maximum allowable viscosity value (5 Pa·s) for stereolithography applications. The adsorption behavior of DISPERBYK-103 on the surface of zirconia powders was characterized by TG and FT-IR, confirming the dispersion effect of dispersant. Contact angle measurements were also conducted to show that the adsorption of DISPERBYK-103 could help to improve the wettability between powder and photocurable resin. Results showed that DISPERBYK-103 was effective for the preparation of suitable slurries for the development of ZrO₂ ceramics through stereolithography.     

Phase formation and lattice distortion of Lu2O3-doped ZrO2 in comparison with Y2O3-doped ZrO2

Lu₂O₃ and Y₂O₃ doping of 8, 11, and 18 mol% in ZrO₂ were prepared by solid solution reaction, aiming to study the phase stabilization of Lu₂O₃-doped ZrO₂ and Y₂O₃-doped ZrO₂ in terms of phase formation and lattice distortion. The Rietveld refinement results indicated that Lu₂O₃-doped ZrO₂ and Y₂O₃-doped ZrO₂ followed the same trend in terms of cubic phase fraction, increasing from 25%–30% (8 mol%) to 95%–100% (11 and 18 mol%). This phase formation was confirmed by observing the same diffraction ring pattern observed for the Lu₂O₃-doped ZrO₂ and Y₂O₃-doped ZrO₂. The Vickers hardness of the Lu₂O₃-doped ZrO₂ was 4.3% higher than that of Y₂O₃-doped ZrO₂ at 8 mol%, but 9.7% and 14.8% lower at 11 and 18 mol%, respectively. This was likely caused by the lattice distortion effect of Y₂O₃ doping overpowering the field strength difference between Lu³⁺ and Y³⁺.     

Thermodynamic modeling and experimental investigation of the MgO-Y2O3-ZrO2 system

Solid-state phase equilibria in the MgO-Y₂O₃-ZrO₂ system as well as the equilibria including liquid were investigated in the whole-compositional range using high-temperature differential thermal analysis (DTA), X-ray diffraction (XRD), and scanning electron microscopy combined with energy dispersive X-ray spectroscopy (SEM/EDX). Isothermal sections at 1493, 1573, 1693, and 1923 K were constructed based on experimental studies. The presence of tie line between MgO and Y₄Zr₃O₁₂ in the temperature range between 1493 and 1573 K was confirmed. The eutectic melting in the MgO-Y₂O₃-ZrO₂ system was established using DTA followed by SEM/EDX microstructure investigation. Based on the obtained experimental results, the thermodynamic database was derived.     

Ni-Na/Zr02-Mn02-Zn0催化合成甲基异丙基酮和二乙基酮（英文）

ZrO2-MnO2-ZnO supports were prepared by the co-precipitation method,and then Ni-Na/ZrO2-MnO2-ZnO catalysts were prepared by the impregnation method.In this paper,the reactions to synthesize methyl isopropyl ketone and diethyl ketone by the one-step synthesis method over this catalyst were studied,and meanwhile,the impact of the catalyst preparation conditions and the reaction conditions on catalyst performance was also investigated.It was observed that under the conditions when Ni loading was 25%,calcination temperature was 400℃ and reduction temperature was 410℃,this catalyst had good catalytic performance on the reaction.The suitable reaction conditions were achieved:reaction temperature was 400℃;reaction at atmospheric pressure;liquid hourly space velocity of raw material of 0.5 h 1 ;and the molar ratio of(methanol)/(methyl ethyl ketone)/(water) was equal to 1/1/1.Under such conditions,the conversion of methyl ethyl ketone could achieve 41.7%,and the overall selectivity of methyl isopropyl ketone and diethyl ketone could achieve 83.3%,which was comparable to the conversion of 38.1% and the selectivity of 82.2% achieved by using palladium as the active material.The good stability made this catalyst have good prospects for industrial application.     

Pt-SO2-4/ZrO2-Al2O3催化剂的制备及其催化正戊烷异构化性能

制备了Pt-SO2-4/ZrO2-Al2O3固体超强酸催化剂,采用XRD,TG-DTA,FT-IR,TPR,SEM,BET,ICP等表征方法对催化剂进行了表征.以正戊烷异构化反应为探针,在高压固定床-色谱联合装置上,评价了催化剂的活性,考察了空速v空、反应温度t、反应压力p和氢与正戊烷摩尔比对正戊烷异构化反应的影响.在...