Na+、K+离子交换对Co-Mo/MCM-41加氢脱硫催化剂的影响

 用偏硅酸钠和正硅酸乙酯作硅源制备了MCM-41（分别记作MCM-41(S)和MCM-41(T)）分子筛，并用Na₂C₂O₄和K₂C₂O₄对MCM-41(S)进行了碱金属离子交换改性。以质量分数0.8 %的二苯并噻吩（DBT）的十氢萘溶液为模型化合物，考察了不同MCM-41担载的Co-Mo硫化物催化剂对DBT的加氢脱硫反应性能。结果表明，MCM-41担载的Co-Mo催化剂加氢活性较低，DBT主要通过直接脱硫反应路径脱硫。其活性顺序为：Co-Mo/MCM-41(T)>Co-Mo/MCM-41(S)>Co-Mo/MCM-41(K)>Co-Mo/MCM-41(Na)。UV-Vis结果表明，部分Co与MCM-41(S)中少量Al发生相互作用，生成了CoAl₂O₄，是造成Co-Mo/MCM-41(S)活性降低的重要因素。而在Co-Mo/MCM-41(K)和Co-Mo/MCM-41(Na)中，除CoAl₂O₄物种之外，碱金属的引入还促进了Co₃O₄物种的形成，使其活性进一步降低。     

硫含量对钴钼型耐硫脱氧剂的脱氧活性影响

研究了工艺气中硫含量对钴钼型耐硫脱氧剂脱氧活性的影响。通过常压微反 -色谱装置测定脱氧剂的本征脱氧活性 ,加压原粒度反应器测定脱氧剂的表观脱氧活性 ,结合实际经验确定了耐硫脱氧剂所需的最低硫含量。还讨论了温度、压力、空速对耐硫脱氧剂脱氧活性的影响。结果表明 ,耐硫脱氧剂完全能满足耐硫变换工艺的要求 ,而且有耐硫变换的作用 ,并对耐硫变换催化剂起到保护作用     

铁钴镍双组分氮化钼催化剂的制备和丙烷氨氧化性能的研究

以氢气和氮气的混合气体为氮化气体与铁钼、钴钼及镍钼双金属氧化物进行程序升温氮化反应合成了铁钼、钴钼及镍钼双金属氮化物催化剂。将铁钼、钴钼和镍钼氮化物分别用于催化丙烷氨氧化反应，研究结果表明，钴钼和镍钼双金属氮化物催化剂具有更高的催化活性和更高的丙烯腈选择性。     

助剂对Co-Mo/r-Al_2O_3耐硫变换催化剂的影响

添加镁、镧、铈、钾其中一种为助剂采用分步浸渍法制备了两个不同 Co/Mo 比系列的 Co-Mo/r-Al_2O_3催化剂,并利用活性评价考察了上述助剂时催化剂活性、热稳定性的影响,结果表明,镁提高了催化剂的活性、热稳定性,尤其是高温活性;镧和铈的加入提高了催化剂的热稳定性;加入钾后较大程度地提高了催化剂的活性,尤其是低温活性,但催化剂热稳定性差,在该样品系列中有一个最佳的 K/r-Al_2O_3比。     

介孔分子筛催化剂Co-Mo/SBA-15的制备及其加氢脱硫性能

 以介孔分子筛SBA-15为载体,采用浸渍法制备了Co-Mo/SBA-15催化剂。采用XRD、BET、FT-IR、TEM等测试手段对样品进行了分析。用0.5% 二苯并噻吩（DBT）的环己烷溶液为模型化合物,在固定床反应器上评价了Co-Mo/SBA-15的催化活性。结果表明,担载金属后的SBA-15分子筛仍然具有高度有序的二维六方介孔结构,金属颗粒高度分散。当MoO₃的负载量增加到25%时,分散度有所降低,部分MoO₃以聚集态存在于载体表面。含5%CoO和25%MoO₃的Co-Mo/SBA-15催化剂具有最高的加氢脱硫活性,硫质量分数由490μ g/g降至11μ g/g,DBT的脱硫率可达97.75%。     

Influence of bath composition on the electrodeposition of cobalt-molybdenum amorphous alloy thin films

Cobalt-molybdenum (Co-Mo) amorphous alloy thin films were deposited on copper substrates by the electrochemical method at pH 4.0. Among the experimental electrodeposition parameters, only the concentration ratio of molybdate to cobalt ions ([ MoO2-4 ]/[CO2 ]) was varied to analyze its influence on the mechanism of induced cobalt-molybdenum codeposition. Voltammetry was one of the main techniques, which was used to examine the voltammetric response, revealing that cobalt-molybdenum codeposi-tion depended on the nature of the species in solution. To correlate the type of the film to the electrochemical response, various co-bait-molybdenum alloy thin films obtained from different [ MoO2-4]/[Co2 ] solutions were tested. Crack-free homogeneous films could be easily obtained from the low molybdate concentrations ([ MoO2-4]/[Co2 ]≈0.05) applying low deposition potentials.Moreover, the content of molybdenum up to 30wt% could be obtained from high molybdate concentration; in this case, the films showed cracks. The formation of these cracked films could be predicted from the observed distortions in the curves of electric cur-rent-time (j-t) deposition transients. The films with amorphous stmeture were obtained. The hysteresis loops suggested that the easily film were obtained when the deposition potential was -1025 mV, and [ MoO2-4]/[Co2 ] was 0.05 in solution, which exhibited a nicer soft-magnetic response.     

一氧化碳变换工序节能改造

阐述了全低变工艺改造的理论依据,介绍了山东滕州鲁南化肥厂全低变工艺改造的必要性,以及改造的内容和节能效果。     

喹啉对Co-Mo/Al_2O_3催化二苯并噻吩加氢脱硫的反应动力学研究

在柴油加氢脱硫(HDS)催化剂FHUDS-5(Co-Mo/Al2O3)上,模拟工业高压搅拌反应釜生产工艺,考察了喹啉对二苯并噻吩(DBT)HDS反应活性的影响,并对其反应动力学进行了研究。结果表明,DBT的HDS反应主要通过加氢路径(HYD)和氢解路径(DDS)进行,符合一级反应动力学模型;当喹啉浓度很低时,其对DBT加氢脱硫反应的抑制作用强烈,但随着喹啉浓度的增加,这种抑制作用不再明显;当n为0.25时,喹啉对DBT加氢脱硫反应活性的影响符合于rDBT=kDBTCDBT/(1+Kn NCn N)动力学模型。     

Cobalt molybdenum carbides as anode electrocatalyst for proton exchange membrane fuel cell

Cobalt molybdenum (Co-Mo) carbides were prepared by the carburization of Co-Mo oxides at temperatures of 723–973 K in a stream of CH₄/H₂ gas. The carburized catalysts were evaluated using a single-stack fuel cell and three-electrode cell. The results showed high activities for the anodic electrooxidation of hydrogen over the Co-Mo catalysts carburized at 873 and 923 K. The 873 K carburized Co-Mo catalyst had the highest activity and achieved 10.9% of the performance of a commercial Pt/C catalyst in a single-stack fuel cell. The XRD, TPC, TPR and XPS results showed that the Co-Mo oxycarbide in the bulk and on the surface are the active species for the hydrogen oxidation reaction.     

A statistical evaluation of preparation conditions on the performance of Ce-promoted Co-Mo Fischer-Tropsch catalyst

This paper describes a statistical approach to the optimal selection of preparation conditions for a ceria-promoted Co-Mo catalyst used during CO hydrogenation. Eight catalyst samples based on a full factorial design were prepared via incipient wetness method. Evaluation was carried out in laboratory packed bed reactor using synthesis gas containing H₂:CO=2 at 280 °C and 110 kPa. BET was unaffected by pH although increased calcination temperature induced only a small drop in total surface area. More significantly, catalysts calcined at low temperature (350 °C) suffered a 3-fold loss in metal surface area when treated at high temperatures (550 °C) while an increase in pH improved the metal area value. pH values above the isoelectric point (IEP=5.65) and low calcination temperature favoured activity and alkene selectivity. High reduction temperature, however, appeared to enhance methane suppression. Additionally, 2-factor interactions were statistically more significant than 3-factor interactions at 95% confidence level. Optimisation of the polynomial models describing the response data was also consistent with qualitative inferences. This paper was presented at the 8th APCChE (Asia Pacific Confederation of Chemical Engineering) Congress held at Seoul between August 16 and 19, 1999.