Advanced Materials Research Vols. 347-353

Abstract: Alkylation of benzene with ethanol for synthesis of ethylbenzene was performed over parent zeolites and zeolites modified with La2O3, such as HMCM-22, HBeta and nano HZSM-5 in a fixed-bed reactor at CO2 flow. The properties of zeolites and catalysts were characterized by XRD, BET and NH3-TPD. The results indicated that zeolite catalysts modified with La2O3 showed high conversion of benzene and high selectivity of ethylbenzene, i.e., 25 % conversion of benzene and 92.72% selectivity of ehtylbenzene over 3%La2O3-HZSM-5(Si/Al=200) respectively. The high selectivity of ethylbenzene is attributed to the proper acid property of modified HZSM-5, and it can be concluded that acid properties is the main factor to affect on this Alkylation. In addition, the deactivation obviously restricted over 5%La2O3-HMCM-22 and 3%La2O3-HZSM-5(Si/Al=200) on time on-stream of reaction, due to enhancement of anti-coking capability and hydrothermal stability after modification.

Abstract: In this paper, catalytic reduction of formic acid to methanol with different catalyst under mild hydrothermal conditions was investigated. Formic acid was successfully converted into methanol using Al as reductant and Cu as a catalyst under mild hydrothermal conditions. The selectivity of conversion from formic acid to methanol was found to be as high as 30% at 300 °C for 9 h with formic acid 60 g∙L^-1, filling rate 35% and 4.35 mmol Al and 12 mmol Cu. The addition of Al₂O₃ was favorable for the synthesis of methanol. Comparing the yield of methanol with the same reaction condition for 3 h without the addition of Al₂O₃, the yield of methanol can be increased by near 100 per cent under the same condition with Al₂O₃ 3 mmol. This process may provide a promising solution to provide methanol as fuel for transportation and mobile devices.

Abstract: A SAPO-34 catalyst is well known to be one of the best catalysts for DME to olefins (DTO) reaction. Main products of the reaction were light olefins such as ethylene, propylene and butenes. However, the main problem is rapid deactivation of the SAPO-34 catalyst due to coke deposition during DTO reaction. In this study, various SAPO-34/ZrO2 catalysts added with ZrO2 were prepared for improving the lifetime and their physicochemical properties have been characterized by XRD and SEM. The DTO reaction over various SAPO-34/ZrO2 catalysts was carried out using a fixed bed reactor. All SAPO-34/ZrO2 catalysts showed similar activity and selectivity in the DTO reaction. The SAPO-34(9wt%)/ZrO2 catalyst was showed the best performance for the catalyst lifetime.

Abstract: Styrenesulfonate grafted multi-walled carbon nanotubes (ss-MWCNTs) were prepared by a simple chemical reaction with soduim 4-styrenesulfonate to reinforce Nafion® membranes for use in direct methanol fuel cells (DMFCs). Although Nafion® membranes have excellent proton conductivity for fuel cell applications, methanol crossover through the Nafion® membrane remains a serious problem for DMFC applications. The prepared ss-MWCNTs had approximately 3.30 wt.% of sulfure and showed styrenesulfonate groups on the ss-MWCNTs. Then, the Nafion® membranes were reinforced with ss-MWCNTs to reduce methanol crossover. The styrenesulfonate groups on the ss-MWCNTs contained sulfonate end groups that enhanced miscibility of MWCNTs in the Nafion® membrance because of affinity of the same sulfonate groups in the ss-MWCNTs and the Nafion® membrane. Further, the phenyl structure of the styrenesulfonate groups on the ss-MWCNTs enhanced thermal stability at high temperature. The Nafion® membranes were reinforced with ss-MWCNTs (1 wt.%) using a solution casting with a certain amount of water and sodium 4-styrenesulfonate. Well-dispersed 1 wt.% ss-MWCNT reinforced Nafion® membranes were prepared, and the water and methanol uptake were investigated for DMFC applications. The methanol uptake value (36.84) of the 1 wt.% ss-MWCNT reinforced Nafion® membranes was reduced compared to that of the cast Nafion® membrane (38.85).

Abstract: A series of Cu-Fe-Co based catalysts prepared by co-impregnation method using different alkali additives was characterized by BET, XRD and FESEM-EDX and investigated under MAS from CO hydrogenation. The results showed that the catalyst Cu25Fe22Co3-Na3/SiO2 has the highest catalytic activity and selectivity of total alcohol and C5+OH. XRD and FESEM-EDX demonstrated the Na3 catalyst exhibited homogeneous distribution of elements and effective synergy effect between Cu and Fe components, thereby performed good catalytic performances for MAS from CO hydrogenation. The presence of a suitable content of alkali promoter was necessary for mixed alcohols synthesis from syngas.

Abstract: The hybrid resin solid acids were prepared by using mesoporous material MCM-41 and porous activated carbon material as support, and their catalytic performance was investigated as well. Comparing with conventional acidic cation exchange resin Amberlyst 15, the hybrid resin prepared under the appropriate conditions show higher surface area and higher catalytic activity in the polymerization of tetrahydrofuran.

Abstract: A series of Ni and Ni-Co were maintained on a mixed support of USY (ultrastable Y) zeolite and active aluminum oxide. The catalysts were characterized by means of element analysis, BET and XRD. The characterization results suggested that the active metal components were introduced without changing the microstructure. Then catalytic hydrocracking activity was studied using AATO (distillate of coal tar) in a tubular reactor. AATO conversion was 39.40% and 41.37% using the 10%Ni/USY catalyst and 10%Ni-6%Co/USY catalyst, the hightest total selectivity of benzene and xylol was 67.1% in 10%Ni-10%Co/USY catalyst than others under the reaction conditions studied [T=480°C, P=4.5MPa, LHSV=3.0h-1].

Abstract: The concepts and application of reactive distillation process were introduced, SCDS was used as a platform was applied to the simulation of reactive distillation of acetic acid and ethanol, and the usage principles and methods of simulated reaction in ChemCAD were introduced. Simulation results and experimental data agreed satisfactorily. It has certain directive significance to real production.

Abstract: The effect of different contents of Ni loaded on USY-zeolite catalyst and the effect of temperature and hydrogen partial pressure on hydrocracking behavior of PRO residual oil were studied. It was observed that the content of Ni showed a great effect on monocyclic selectivity. The overall conversion decreased at first and then increased with reaction temperature, while the impacts of temperature on monocyclic selectivity varied with hydrogen partial pressure. In addition, the overall conversion increased with the increase of hydrogen partial pressure and the maximum overall conversion was 45.4% at 440°C. The increasing of hydrogen partial pressure is slightly helpful to monocyclic selectivity.

Abstract: The objective of this study was to investigate the performance of SMA mixtures with AMBS (Activated Mineral Binder Stabilizer), a new type of bitumen stabilizer, comparing with SMA with fibers. In the paper, after a short introduction about the modification mechanism, general performances of these mixtures were researched through a series of laboratory tests. The results show that the performance of SMA with AMBS meets the requirement of criterion. It shows better results than SMA with fibers in Immersed Marshall test, Rutting test, Low temperature bending test and etc. Besides, with less consume of energy and less CO2 emission, the comparison of the environmental indicators shows a quantitative decline in the negative environmental economic cost per ton SMA mix, when using the activated-mineral binder-stabilizer as compared to the cellulose fibers. In a word, there are tremendous promotion value and good engineering application prospect in AMBS