Yanyong Liu

Bio: Yanyong Liu is an academic researcher from National Institute of Advanced Industrial Science and Technology. The author has contributed to research in topics: Catalysis & Methanol. The author has an hindex of 29, co-authored 78 publications receiving 2457 citations. Previous affiliations of Yanyong Liu include University of Tokyo.

Renewable Diesel Production from the Hydrotreating of Rapeseed Oil with Pt/Zeolite and NiMo/Al2O3 Catalysts

Abstract: As an alternative way to produce diesel hydrocarbons, the hydrocracking of rapeseed oil was studied on three different types of bifunctional catalysts: Pt/H-Y, Pt/H-ZSM-5, and sulfided NiMo/γ-Al2O3. Experiments were carried out in a batch reactor over a temperature range of 300−400 °C and initial hydrogen pressures from 5 to 11 MPa. The reaction time was limited to 3 h to prevent a high degree of cracking. The Pt-zeolite catalysts had a strong catalytic activity for both cracking and hydrogenation reactions, and therefore a higher severity was required to reach a relatively high oil conversion into liquid hydrocarbons. With dependence on the activity of the acid sites of the catalysts, the results show a trade-off between the yield of green diesel and the degree of isomerization, which had a direct effect on the cold properties of the diesel. Among the three catalysts, hydrocracking on Ni-Mo/γ-Al2O3 gave the highest yield of liquid hydrocarbons in the boiling range of the diesel fraction, i.e., green dies...

Highly active copper/ceria catalysts for steam reforming of methanol

Abstract: The Ce1−xCuxO2−x mixed oxides were synthesized using the coprecipitation method. The X-ray diffraction (XRD) patterns and the temperature-programmed reduction (TPR) profiles indicated that the Cu2+-ions were dissolved into the CeO2 lattices to form a solid solution by calcination at 723 K when x<0.2 in the Ce1−xCuxO2−x mixed oxides. The Ce1−xCuxO2−x mixed oxides were reduced to form the Cu/CeO2 (cop) catalysts for the steam reforming of methanol. The activity and selectivity of Cu/CeO2 (cop) were compared with those of Cu/ZnO, Cu/Zn(Al)O and Cu/Al2O3. All the Cu-containing catalysts tested in this study showed high selectivities to CO2 (over 97%) and H2. A 3.9 wt.% Cu/CeO2 (cop) catalyst showed a conversion of 53.9% for the steam reforming of methanol at 513 K, which was higher than the conversions over Cu/ZnO (37.9%), Cu/Zn(Al)O (32.3%) and Cu/Al2O3 (11.2%) with the same Cu loading under the same reaction conditions. The high activity of the 3.9 wt.% Cu/CeO2 (cop) catalyst may be due to the highly dispersed Cu metal particles and the Cu+ species stabilized by the CeO2 support. Slow deactivation was observed over the 3.9 wt.% Cu/CeO2 (cop) catalyst at 493 and 513 K. The activity of the deactivated catalysts can be regenerated by calcination in air at 723 K, followed by reduction in H2 at 673 K. Such success indicated that the carbonaceous deposit on the catalysts surface caused the catalysts’ deactivation. The temperature-programmed oxidation (TPO) method indicated that the amounts of coke on the 3.9 wt.% Cu/CeO2 (cop) catalyst were 0.8 wt.% at 493 K and 1.7 wt.% at 513 K after 24 h on stream.

Production of Synthetic Diesel by Hydrotreatment of Jatropha Oils Using Pt−Re/H-ZSM-5 Catalyst

Abstract: Renewable green diesel-type alkanes can be produced by hydrotreating jatropha oil and vegetable oils at standard hydrotreating conditions (ie, 543−573 K) with Pt/H-ZSM-5 catalysts, which are active under the weight ratio of jatropha or vegetable oil/catalyst of 1 The carbon molar yield of straight chain C15−C18 alkanes was ∼80% for hydrotreating pure jatropha oil However, under the jatropha oil/catalyst weight ratio of 10, being important from a practical point of view, the alkanes yield falls to only 23% Under a high jatropha oil/catalyst ratio of 10, rhenium-modified Pt/H-ZSM-5 catalyst is found to be effective for raising the C15−C18 alkanes yield The yield of C15−C18 alkanes is 67% at an optimun Re/Al molar ratio of 08 Investigation of catalyst natures indicates that metallic Pt and Re are independently present on the surface, but synergism of these two metals could play an important role in the hydrotreating reaction, even at a high ratio of jatropha oil/catalyst of 10 The reaction pathway

Hydrotreatment of Vegetable Oils to Produce Bio-Hydrogenated Diesel and Liquefied Petroleum Gas Fuel over Catalysts Containing Sulfided Ni–Mo and Solid Acids

Abstract: Biohydrogenated diesel (BHD) and liquefied petroleum gas (LPG) fuel were produced by the hydrotreatment of vegetable oils over Ni–Mo-based catalysts in a high-pressure fixed-bed flow reaction system at 350 °C under 4 MPa of hydrogen. Because triglycerides and free fatty acids underwent the hydrogenation and deoxidization at the same time during the reaction, various vegetable oils (jatropha oil, palm oil, and canola oil) were converted to mixed paraffins by the one-step hydrotreatment process although they contained quite different amounts of free fatty acids. Ni-Mo/SiO2 formed n-C18H38, n-C17H36, n-C16H34, and n-C15H32 as predominant products in the hydrotreatment of jatropha oil. These long normal hydrocarbons had high melting points and thus gave the liquid hydrocarbon product over Ni-Mo/SiO2 a high pour point of 20 °C. Either Ni-Mo/H-Y or Ni-Mo/H-ZSM-5 was not suitable for producing BHD from jatropha oil because a large amount of gasoline-ranged hydrocarbons was formed on the strong acid sites of zeol...

Steam reforming of methanol over Cu/CeO2 catalysts studied in comparison with Cu/ZnO and Cu/Zn(Al)O catalysts

Abstract: A series of Ce1-xCuxO2-δ mixed oxides were synthesized using a co-precipitation method and tested as catalysts for the steam reforming of methanol. XRD patterns of the Ce1-xCuxO2-δ mixed oxides indicated that Cu2+ ions were dissolved in CeO2 lattices to form a solid solution by calcination at 773K when x < 0.2. A TPR (temperature-programmed reduction) investigation showed that the CeO2 promotes the reduction of the Cu2+ species. Two reduction peaks were observed in the TPR profiles, which suggested that there were two different Cu2+ species in the Ce1-xCuxO2-δ mixed oxides. The TPR peak at low temperature is attributed to the bulk Cu2+ species which dissolved into the CeO2 lattices, and the peak at high temperature is due to the CuO species dispersed on the surface of CeO2. The Ce1-xCuxO2-δ mixed oxides were reduced to form Cu/CeO2 catalysts for steam reforming of methanol, and were compared with Cu/ZnO, Cu/Zn(Al)O and Cu/AL2O3 catalysts. All the Cu-containing catalysts tested in this study showed high selectivities to CO2 (over 97%) and H2. A 3.8wt% Cu/CeO2 catalyst showed a conversion of 53.9% for the steam reforming of methanol at 513K (W/F = 4.9 g h mol-1), which was higher than that over Cu/ZnO (37.9%), Cu/Zn(Al)O (32.3%) and Cu/AL2O3 (11.2%) with the same Cu loading under the same reaction conditions. It is likely that the high activity of the Cu/CeO2 catalysts may be due to the highly dispersed Cu metal particles and the strong metalsupport interaction between the Cu metal and CeO2 support. Slow deactivations were observed over the 3.8wt% Cu/CeO2 catalyst at 493 and 513K. The activity of the deactivated catalysts can be regenerated by calcination in air at 773K followed by reduction in H2 at 673K, which indicated that a carbonaceous deposit on the catalyst surface caused the catalyst deactivation. Using the TPO (temperature-programmed oxidation) method, the amounts of coke on the 3.8wt% Cu/CeO2 catalyst were 0.8wt% at 493K and 1.7wt% at 513K after 24h on stream.

Fundamentals and Catalytic Applications of CeO2-Based Materials

Abstract: Cerium dioxide (CeO2, ceria) is becoming an ubiquitous constituent in catalytic systems for a variety of applications. 2016 sees the 40th anniversary since ceria was first employed by Ford Motor Company as an oxygen storage component in car converters, to become in the years since its inception an irreplaceable component in three-way catalysts (TWCs). Apart from this well-established use, ceria is looming as a catalyst component for a wide range of catalytic applications. For some of these, such as fuel cells, CeO2-based materials have almost reached the market stage, while for some other catalytic reactions, such as reforming processes, photocatalysis, water-gas shift reaction, thermochemical water splitting, and organic reactions, ceria is emerging as a unique material, holding great promise for future market breakthroughs. While much knowledge about the fundamental characteristics of CeO2-based materials has already been acquired, new characterization techniques and powerful theoretical methods are dee...

Beyond directing groups: transition-metal-catalyzed C-H activation of simple arenes.

Abstract: The use of coordinating moieties as directing groups for the functionalization of aromatic CH bonds has become an established tool to enhance reactivity and induce regioselectivity. Nevertheless, with regard to the synthetic applicability of CH activation, there is a growing interest in transformations in which the directing group can be fully abandoned, thus allowing the direct functionalization of simple benzene derivatives. However, this approach requires the disclosure of new strategies to achieve reactivity and to control selectivity. In this review, recent advances in the emerging field of non-chelate-assisted CH activation are discussed, highlighting some of the most intriguing and inspiring examples of induction of reactivity and selectivity.