Effect of Different Loadings on the Performance of Ni2P/Al2O3 Catalysts for Low-Temperature Thioethering and Selective Hydrogenation of Diolefins in Liquefied Petroleum Gas

In this study, different loadings of x%Ni₂P/γ-Al₂O₃(x = 6%, 9%, 12%, 15%, 18%) catalysts with aluminum oxide(Al₂O₃) as the carrier, nickel chloride(NiCl₂) as the nickel(Ni) source, and ammonium hypophosphite(NH₄H₂PO₂)as the phosphorus(P) source were prepared by the equal volume impregnation method to investigate the effects of different loadings on the performance of the selective hydrogenation of ...     

新鲜态Mo2C/γ-Al2O3 催化剂上丁二烯加氢反应的原位红外光谱研究

The surface species formed from the adsorption of 1,3-butadiene and 1,3-butadiene hydrogenation over the freshMo2C/γ-Al2O3 catalyst was studied by in situ IR spectroscopy. It is found that 1,3-butadiene adsorption on the Mo2C/γ-Al2O3catalyst mainly forms π-adsorbed butadiene （πs and πd） and σ-bonded surface species. These species are adsorbed mainly onthe surface Moδ＋ （0〈δ〈2） sites as evidenced by co-adsorption of 1,3-butadiene and CO on the fresh Mo2C/γ-Al2O3 catalyst.The IR spectrometric analysis show that hydrogenation of 1,3-butadiene over fresh Mo2C/γ-Al2O3 catalyst produces mainlybutane coupled with a small portion of butene. The selectivity of butene during the hydrogenation of 1,3-butadiene overfresh Mo2C/γ-Al2O3 catalyst might be explained by the adsorption mode of adsorbed 1,3-butadiene. Additionally, the activesites of the fresh Mo2C/γ-Al2O3 catalyst may be covered by coke during the hydrogenation reaction of 1,3-butadiene. Thetreatment with hydrogen at 673 K cannot remove the coke deposits from the surface of the Mo2C/γ-Al2O3 catalyst.     

Effect of Ammonia on the Performance of Catalysts for Selective Hydrogenation of 1-Methylnaphthalene

The effect of ammonia on the catalytic performance for 1-methylnaphthalene(1-MN) selective hydrogenation saturation was studied with Co-Mo/γ-Al_2O_3, Ni-W/γ-Al_2O_3, Ni-Mo/γ-Al_2O_3, and Ni-Mo-W/γ-Al_2O_3 catalysts. The results indicated that Ni-Mo-W/γ-Al_2O_3 catalyst exhibited the best performance for saturation of 1-MN. The introduction of NH3 remarkably inhibited the hydrogenation of 1-MN in the dynamic control area, but it had no effect in the thermodynamic control area. Besides, the mono-aromatics selectivity on the Ni-Mo-W and Ni-Mo catalysts was enhanced. However, it had little effect on the Ni-W and Co-Mo catalysts.     

Synthesis of Hierarchical Porous Fe2O3/Al2O3 Materials and Study on Catalytic Viscosity Reduction of Heavy Oil

Fe₂O₃ nanoparticles were first dispersed in a sol solution containing an aluminum component introduced by an initial doping method. Composite catalyst Hierarchical Porous Fe₂O₃/Al₂O₃ materials(HPFA) were then synthesized through a sol-gel method via phase separation. The performance of HPFA was compared with that of Fe₂O₃ nanoparticle catalysts. The structure of the composite catalyst was characterized by sca...     

Studies on the Hydrogenation of Acetonitrile over Fresh Mo_2C/γ-Al_2O_3 Catalyst by In-situ IR Spectroscopy

The adsorption of acetonitrile, the co-adsorption of acetonitrile with CO, and hydrogenation of acetonitrile on fresh Mo2C/γ-Al2O3 catalyst were studied by in situ IR spectroscopy. It was found out that CH3CN exhibited strong interaction with the fresh Mo2C/γ-Al2O3 catalyst and was adsorbed mainly on Moδ+ sites of fresh Mo2C/γ-Al2O3 catalyst. Moreover, CH3CN could affect the shifting of IR spectra for CO adsorption towards a lower wave number. The IR spectroscopic study on acetonitrile hydrogenation showed that CH3CN could be easily hydrogenated in the presence of H2 on the Mo2C/γ-Al2O3 catalyst. Furthermore, it was observed that CH3 CN could be selectively hydrogenated to imines on fresh Mo2C/γ-Al2O3 catalyst. Additionally, the active sites of fresh Mo2C/γ-Al2O3 catalyst might be covered with coke during the hydrogenation reaction of acetonitrile. The treatment of catalyst with hydrogen at 673 K could not completely remove coke deposits on the surface of the Mo2C/γ-Al2O3 catalyst.     

Promotional Effect of CoO(OH) on Selective Hydrogenation of Maleic Anhydride to γ-Butyrolactone over Supported Ruthenium Catalyst

A decorated ruthenium catalyst was prepared by the coprecipitation method and used for the selective hydrogenation of maleic anhydride(MA) to γ-butyrolactone(GBL). The as-prepared catalyst was characterized by XRD, TGDTG and N2 adsorption techniques. The characterization tests revealed that the catalyst carrier was composed of monoclinic zirconia(m-ZrO2) and hydroxyl cobalt oxide(CoO(OH)). The hydrogenation results showed that the content of CoO(OH), the reaction temperature, the hydrogen pressure and the reaction time significantly affected the catalytic selectivity to GBL. The promotional effect of CoO(OH) was remarkable, which led to an obvious increase in GBL selectivity. An 100% MA conversion and 92.0% selectivity to GBL were achieved over the Ru/ZrO2-CoO(OH)(35%) catalyst in water solvent under the conditions involving a reaction temperature of 180 ℃, a hydrogen pressure of 3.0 MPa, and a reaction time of 6 h.     

Ni2P-MoS2/γ-Al2O3催化剂的加氢路径脱硫性能

A series of highly active Ni2P-MoS2/γ-Al2O3 catalysts were prepared and characterized, the catalytic performanceof which was evaluated through hydrodesulfurization of dibenzothiophene. The result indicated that when the amount ofNi2P was 4%, the catalyst showed a relatively high activity to provide a reliable reference for the hydrodesulfurization pathwayin comparison with the conventional NiMo and NiMoP catalysts. The physicochemical properties of the catalysts werecorrelated with their catalytic activity and selectivity on hydrodesulfurization. The stacking number of active MoS2 phaseswas important for influencing the hydrogenation activity.     

柴油在硅藻土分散 NiMoW硫化催化剂上深度加氢脱硫研究

Diatomite-dispersed NiMoW catalyst was prepared and characterized, and the activity of catalyst samples was tested during the HDS reaction of FCC diesel. Sulfur compounds in the feedstock and the hydrogenated products obtained over different catalysts were determined by GC-PFPD. The test results showed that the diatomite-dispersed NiMoW catalyst had high hydrodesulfurization activity for FCC diesel, which could be contributed to the excellent hydrogenation perfor- mance of the said catalyst. Characterization of catalyst by TEM and XRD indicated that the diatomite-dispersed NiMoW catalyst possessed higher layer stacking, larger curvature of MoS2 or WS2, and segregated Ni3S2 crystals relative to the sup- ported catalyst. This kind of structure leads to high hydrogenation activity of the diatomite-dispersed NiMoW catalyst.     

Residue Upgrading in Slurry Phase over Ultra-fine NiMo/γ-Al_2O_3 Catalyst

In this article, residual oil hydroconversion was studied in slurry phase in the presence of fine solid Ni Mo/γ-Al2O3 catalyst and the effects of operating conditions were carefully studied. The results showed that residue conversion was only affected by the reaction temperature and reaction time. The coke yield increased with a higher reaction temperature, a bigger catalyst particle size, a longer reaction time, a lower initial hydrogen pressure and a lower catalyst concentration. Heteroatoms removal rate increased with a higher reaction temperature, a longer reaction time, a higher initial hydrogen pressure, a higher catalyst concentration, and a smaller catalyst particle size. The role of catalyst in the slurry bed technology was discussed and its function could be stated as follows: the metal was applied to activate the hydrogen atoms for removing heteroatoms and saturating aromatics, while the support of the catalyst was used to prevent the mesophase coalescence for reducing coke formation.     

Application of Acid Modified Catalysts with Different SiO2 Contents in the Hydrocracking of Light Cycle Oil for Light Aromatics Production

A series of functionalized USY/SiO₂ zeolite composite supports were synthesized using the coating coprecipitation method, with tetraethyl orthosilicate(TEOS) as the silicon source and different ratios of USY to TEOS. Active metals nickel(Ni) and molybdenum(Mo) were loaded onto the supports using the impregnation method. Finally, a series of hydrogenation catalysts were synthesized. The characterization results showed that, compared with the USY catalyst, the addition of a certain quan...     

Preparation and Cracking Performance of FCC Co-Catalyst for Enhancing Light Oil Production

In this paper, a FCC co-catalyst for enhancing the light oil production was prepared by the sol-gel method, and its effect on the performance of residue cracking catalysts was evaluated in a CCFFB reactor. The test results indicated that the liquid product yield increased obviously, after the surface of FCC equilibrium catalyst was impregnated with the co-catalyst. The yields of dry gas, slurry and coke decreased, while the diesel yield changed slightly. And the crackability of residue was increased; the rate of coke deposition on catalyst surface was decreased, with the thermal cracking reactions inhibited. All these results showed that the co-catalyst could improve the density of acid sites and change the catalyst acidity, which could promote to prolong the catalyst activity by depositing the co-catalyst on the surface of FCC equilibrium catalysts.     

Influence of Crystal Size of USY Zeolite on Performance of Hydro-upgrading Catalysts

The effect of crystal size of USY zeolite on the performance of hydro-upgrading catalysts for treating catalytically cracked(FCC) LCO(light cycle oil) was studied.Three W-Ni catalysts supported on USY zeolites with different crystal sizes and Al2O3 were prepared by impregnation method.The catalysts were characterized by XRD and BET methods,and evaluated in a micro-reactor using tetralin as the model compound and in an 100-mL hydrogenation test unit using FCC LCO as the feedstock.By contrast,catalyst made from smaller crystal-size USY zeolite had higher external surface area and shorter pore length,having more hydrogenation activity sites and short contact time of reactant molecules with acidity sites.The evaluation results showed that the catalyst prepared on the basis of small crystal-size USY zeolite had higher tetralin conversion and better hydro-upgrading performance for treating FCC LCO.     

Reverse Microemulsion Synthesis and Characterization of Pd-Ag Bimetallic Alloy Catalysts Supported on Al2O3 for Acetylene Hydrogenation

Pd-Ag bimetallic alloy nanoparticles were synthesized by the reverse microemulsion method,and then deposited on Al2O3 to form the supported catalyst.The nanoparticles of Pd-Ag and Pd-Ag/Al2O3 samples were characterized by UV/Vis,HRTEM,EDX,XRD,and XPS.The test results indicated that Pd-Ag bimetallic alloy nanoparticles with a size of about 2 nm and a face-centered cubic(fcc) structure were formed in the measured area of microemulsion.The growth of nanoparticles was effectively limited within the droplet of micoremulsion.TEM image exhibited that the Pd-Ag alloy nanoparticles were well-dispersed on the Al2O3 support.The catalytic performance of various catalysts for selective hydrogenation of acetylene showed that a higher acetylene conversion and selectivity to ethylene upon acetylene hydrogenation was achieved on a nano-sized Pd-Ag bimetallic catalyst with a Pd/Ag alloy supported molar ratio of 1:1.5.     

Two-Stage Hydrogenation Modification of C_9 Petroleum Resin over NiWS/γ-Al_2O_3 and PdRu/γ-Al_2O_3 Catalysts in Series

Hydrogenation modification is one of the most important ways to produce high-quality petroleum resin.The colorless C9 petroleum resin(C9PR) was obtained by two-stage catalytic hydrogenation over NiWS/γ-Al2O3 catalyst and PdRu/γ-Al2O3 catalyst connected in series.Via the hydrogenation reaction,aromatic rings in C9PR were converted to alicyclic rings,and its color was reduced from Gardner color grade No.11 to Gardner color grade No.0.The optimum Ni/W atomic ratio was found to be close to 0.23,while the optimum Pd/Ru atomic ratio was close to 3.80.The TEM results showed that the morphology and size of sulfide or metal particles of the two kinds of catalysts remained almost unchanged after the reaction was carried our for 1 204 hours,attesting to their good catalytic stability.     

水溶性双金属催化剂催化氯代硝基苯高效选择性加氢制备氯代苯胺

Selective hydrogenation of chloronitrobenzene(CNB) to chloroaniline(CAN) catalyzed by water-soluble Ru/Pt bimetallic catalyst in an aqueous-organic biphasic system was studied. It was found that the catalytic activity increased obviously due to the addition of platinum. Ru/Pt bimetallic catalysts exhibited a strong synergistic effect when the molar ratio of Pt was in the range of 5%—80%. Under the mild conditions including a temperature of 25 ℃, a hydrogen pressure of 1.0 MPa and a Pt molar ratio of 20%, the conversion of p-chloronitrobenzene(p-CNB) reached 99.9%, with the selectivity to p-chloroaniline(p-CAN) equating to 99.4%. The Ru/Pt catalyst also showed high activity and selectivity for the hydrogenation of other chloro- and dichloro-nitrobenzenes with different substituted positions. In addition, the catalyst can be recycled five times without significant loss of activity.     

催化裂化柴油在NiMoW/Al2O3催化剂上选择性加氢动力学研究

n order to investigate the hydrofining unit of LTAG technology, the selective hydrogenation saturation process of PAHs was studied on the NiMoW/Al2O3 catalyst as there is high content of PAHs in FCC light cycle oil (LCO). Based on the study of parameter factors and the reversible hydrogenation reaction law principal of aromatics, PAHs in the selective hydrogenation process could be effectively simulated by the modeled CH group and CH2 group, and the selective saturation model could be further established in this process including the HDN and HDS kinetic models. The results showed that the kinetic models above could fit the experimental data perfectly and predict the content of S, N and aromatics in the selective hydrogenation products of LCO effectively, which could provide theoretical support for the optimization of industrial operation.     

Preparation of a highly efficient Pt/USY catalyst for hydrogenation and selective ring-opening reaction of tetralin

Ultrastable Y zeolite(USY)-supported Pt catalyst was prepared by gas-bubbling-assisted membrane reduction. The influence of reaction conditions and the metal and acid sites of catalysts on the catalytic performance of catalyst in hydrogenation and selective ring opening of tetralin, 1,2,3,4-tetrahydronaphthalene(THN), was studied. It was found that the optimal reaction conditions were at a temperature of 280 °C, hydrogen pressure of 4 MPa, liquid hourly space velocity of 2 h~(-1) and H_2/THN ratio of 750. Under these optimal conditions, a high conversion of almost 100% was achieved on the 0.3 Pt/USY catalyst. XRD patterns and TEM images revealed that Pt particles were highly dispersed on the USY, favorable to the hydrogenation reaction of tetralin. Ammonia temperature-programmed desorption and Py-IR results indicated that the introduction of Pt can reduce the acid sites of USY, particularly the strong acid sites of USY. Thus, the hydrocracking reaction can be suppressed.     

Methanol and DME Co-production from CO2 hydrogenation over hybrid catalysts

Catalytic hydrogenation of CO2 into methanol and dimethyl ether was carried out over hybrid catalysts consisting of methanol-synthesis catalyst and zeolite. The methanol-synthesis catalyst, Cu/ZnO/Al2O3, was prepared by a co-precipitation method. Then it was physically mixed with HZSM-5 zeolite at weight ratios of 2：1, 1：1 and 1：2. The CO2 hydrogenation reaction was conducted in a fixed-bed microreactor at 250℃ and 40 bar in pre-mixed H2/CO2 feed with H2：CO2 molar ratios of 3：1 and 7：1. Products detected include methanol, dimethyl ether, carbon monoxide and water. Conversion of CO2 and yield of oxygenated products were influenced by the weight ratio of Cu/ZnO/Al2O3：HZSM-5 in the hybrid system and also the feed ratio. The Cu/ZnO/Al2O3： HZSM-5 hybrid at 1：1 resulted in methanol yield of 22.0% and was found to be an efficient hybrid catalyst for the CO2 hydrogenation reaction.     

球形多孔γ-Al2O3的制备及刚果红吸附研究

以异丙醇铝为铝源，硝酸为胶溶剂，使用油氨柱成型法制备出毫米级球形多孔γ-Al₂O₃。采用XRD、SEM、TEM、TG和N₂吸附-脱附等方法研究了醇类溶剂对γ-Al₂O₃多孔结构的影响，并探究了球形γ-Al₂O₃对刚果红(CR)水溶液的吸附性能。实验结果表明，处理溶剂的种类可影响球形γ-Al₂O₃多孔结构，介孔和微米大孔随有机溶剂分子的增大而增大；正己醇溶剂处理得到的球形γ-Al₂O₃在1 h对CR溶液吸附效果最好，异丙醇处理得到球形γ-Al₂O₃在4 h吸附效果最好。     

Study on the Effect of Catalyst Properties on Residue Hydroconversion

The effect of catalyst properties on residue oil hydroconversion was studied at moderate operating conditions(at a temperature of 400 ℃, an initial hydrogen pressure of 10 MPa, and a reaction time of 4 h) in a batch mode slurry phase with different catalyst samples. The results showed that the catalyst acidity had a good effect on residue conversion and MCR(micro carbon residue) conversion but brought about higher coke yield. Residue conversion was thermally induced but the catalyst acidity changed its conversion route. A catalyst with higher metal loading, higher hydrogenation activity and appropriate pore size had higher sulfur and metal removal rate, higher MCR conversion and also a lower coke formation. The activity of spent commercial catalyst AS1 and DS1 was slightly lower than the corresponding fresh ones but was still high enough for residue oil hydroconversion. It assumes that the role of the catalyst is to activate hydrogen species toward reaction with an aromatic carbon radical to yield a cyclohexadienyl type intermediate which will turn into liquid and also to absorb the mesophase which can easily aggregate to form coke.