GREEN CHEMISTRY
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2014
·Vol. 17
·期 3
·1710-1717
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IF 6.852
Meng-Yuan Chen,Yao-Bing Huang,Huan Pang,Xin-Xin Liu,Yao Fu
Phenolic compounds derived from lignin are important feedstocks for the sustainable production of alkane fuels with C6–C9 carbons. Hydrodeoxygenation (HDO) is the main chemical process to remove oxygen-containing functionalities. Here, we have reported the HDO of phenols in a biphasic H2O/n-dodecane system. A series of supported Ru catalysts were prepared, characterized and explored for the reaction among which Ru/CNT showed the highest catalytic activity towards the production of alkanes. The model reaction with eugenol achieved a high conversion (>99%) and a high alkane selectivity (98%), which was much higher than the results from the monophasic system (56.5% yield of alkanes in H2O). The reaction conditions including reaction temperature, hydrogen pressure and the ratio of H2O/n-C12H26 were optimized. The kinetic experiments revealed that eugenol was first hydrogenated to 4-propyl-guaiacol, and then deoxygenated into 4-propyl-cyclohexanol which was the main detected intermediate of the reaction. After that, 4-propyl-cyclohexanol was dehydrated and hydrogenated into propylcyclohexane. Moreover, various phenols and dimeric lignin model compounds were also successfully converted into alkanes in the biphasic systems. The construction of the biphasic solvent-Ru/CNT catalyst system highlights an efficient route for the conversion of lignin-derived phenolic compounds to biofuels.
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JOURNAL OF POWER SOURCES
·
2014
·
IF 5.211
Qilu Yao,Weimei Shi,Gang Feng,Zhang-Hui Lu,Xiaoliang Zhang,Duanjian Tao,Dejing Kong,Xiangshu Chen
Ru@SiO 2 core–shell structured nanospheres have been prepared via a one-pot synthetic route in a NP-5/cyclohexane reverse micelle system and characterized by XRD , SEM , TEM, N 2 adsorption–desorption, and H 2 temperature programmed desorption. The characterized results show that ultrafine Ru nanoparticles (NPs) of around 2 nm are effectively embedded in the center of well-proportioned spherical and porous silica nanospheres (∼25 nm in diameter). Interestingly, the number of Ru NPs increases inside the spherical particles of SiO 2 as the increase of Ru loading. The as-synthesized Ru@SiO 2 exhibits high catalytic activity and good durability for hydrogen generation from the aqueous of ammonia borane (AB) complex under ambient atmosphere at room temperature . The hydrolysis activation energy of Ru@SiO 2 was estimated to be about 38.2 kJ mol −1 , which is lower than most of the reported activation energy values for the same reaction using many different Ru-based and other noble metal containing catalysts, indicating the superior catalytic performance of these core–shell structured nanospheres.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2014
·
IF 2.235
Qi-Ying Liu,Yu-He Liao,Tie-Jun Wang,Chi-Liu Cai,Qi Zhang,Noritatsu Tsubaki,Long-Long Ma
ZrP with large surface, mesoporous volume, and size was prepared. Its catalytic performance was evaluated in hydrolytic hydrogenation of cellulose to sorbitol/mannitol combined with commercial Ru/C. A significantly enhanced sorbitol/mannitol yield was obtained as compared with that of the water-soluble acidic phosphates and buffer solution of potassium acid phthalate combined with the same Ru/C. The enhanced yield was attributed to the Lewis and Brönsted acid on ZrP surface improving the surface’s absorption and activation for cellulose and accelerating the rate-determined hydrolysis step. The maximal sorbitol/mannitol yield of 63% and 81% could be obtained by using microcrystalline and ball milling cellulose as the feedstock, respectively. The ZrP combined with Ru/C was adaptable to the high concentrated cellulose and obtained 5.8 wt % of sorbitol/mannitol concentration. The remarkably enhanced cellulose hydrolysis by ZrP sharply decreased the use of Ru/C, which is significant for the essential application.
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CATALYSIS LETTERS
·
2013
·Vol. 144
·期 2
·268-277
·
IF 2.244
Ding Yue,Li Xiaohong,Pan Huiyan,Wu Peng
Abstract Ru nanoparticles entrapped in ordered mesoporous carbons (CMK-3) served as an efficient and reusable catalyst for liquid-phase hydrogenation of benzaldehyde and its derivatives under our tested conditions (medium hydrogen pressure, room temperature, water as solvent). The Ru nanoparticles can be well stabilized by CMK-3 ordered mesoporous carbons so that the Ru leaching was below the detection limit of ICP-AES. Therefore, the Ru/CMK-3 catalyst can be used for at least five times without distinct loss in activity or selectivity for the hydrogenation of benzaldehyde. It is worthy of note that the Ru/CMK-3 catalyst was more efficient than the commercial Ru/C and homemade Ru/AC catalyst for the liquid-phase hydrogenation of benzaldehyde. The Ru/CMK-3 catalyst can also catalyze the liquid-phase hydrogenation of nitrobenzene and its derivatives with high conversions and excellent selectivities under optimal conditions. Graphical Abstract
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FUEL
·
2015
·
IF 3.52
Yujing Weng,Songbai Qiu,Chenguang Wang,Lungang Chen,Zhengqiu Yuan,Mingyue Ding,Qi Zhang,Longlong Ma,Tiejun Wang
In this work, a dual-bed aqueous catalysis system with Ru/C as catalyst was proposed for the liquid alkane (pentane/hexane: C5/C6) production from acid biomass hydrolysate. The low temperature (413 K) hydrogenation of biomass-derived carbohydrates into polyols was carried out in the first fixed-bed. The high temperature (523 K) hydrodeoxygenation (HDO) of polyols into alkanes was carried out in the down-stream bed. To screen the optimal reaction conditions, glucose and sorbitol were chosen for model tests. Whereby, reactor types, solution pH value, mineral acid, reaction temperature, pressure and sorbitol concentrations were studied. A maximum C5/C6 alkane yield of 61.9% was achieved from 20 wt% sorbitol solution (pH = 1.5) under 523 K and 4 MPa H 2 pressure in the fixed-bed reactor. For cassava and corncob hydrolysate, C5/C6 alkane yield of 38.8% and 44.1% were obtained, respectively.
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GREEN CHEMISTRY
·
2016
·Vol. 18
·期 20
·5510-5517
·
IF 8.506
Guang-Yue Xu,Jian-Hua Guo,Yan-Chao Qu,Ying Zhang,Yao Fu,Qing-Xiang Guo
Cyclohexanol and alkyl cyclohexanol are important chemical intermediates. It is meaningful to prepare cyclohexanols from non-fossil-based biomass. Here we report Ru/ZrO2–La(OH)3, a metal-solid base bifunctional catalyst, to show its excellent performance on the partial hydrodeoxygenation of lignin-derived phenols. Guaiacol could be converted to cyclohexanol with a 91.6% yield in water. Alkyl phenols with one or two methoxy groups were converted into alkyl cyclohexanols with yields over 86.9%. The catalyst had good activity of removing a methoxy group and retaining a hydroxyl group. In this catalyst, Zr and La interacted with each other to form a mixed (hydr)oxide, thus making ZrO2–La(OH)3 a stable support. Ru was highly dispersed on the ZrLa support. The pathway from guaiacol to cyclohexanol was investigated and proposed as two parallel ways, demethoxylation followed by hydrogenation (I), the saturation of the aromatic ring through hydrogenation and then demethoxylation through direct hydrogenolysis (II).
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Nanoscale
·
2016
·Vol. 8
·期 25
·12812-12818
·
IF 7.76
Zhuoqing Lin,Wenlong Chen,Ying Jiang,Ting Bian,Hui Zhang,Jianbo Wu,Yong Wang,Deren Yang
PtRu bimetallic particles are well-known commercial catalysts with promising performance for methanol oxidation. However, shape-controlled synthesis of PtRu bimetallic nanocrystals, especially for the platonic structures with {100} (e.g., cubes) or {111} facets (e.g., icosahedra) exposed towards catalysis, has met only limited success due to the different crystal structures of Pt and Ru. Here we report a facile approach to the synthesis of Ru decorated Pt bimetallic cubes and icosahedra in a mixed solvent. We found that the cubes were formed in the solvent containing N,N-dimethylmethanamide (DMF) and oleylamine (OAm) possibly due to the selective adsorption of CO on Pt{100} arising from the decomposition of DMF catalyzed by a Ru salt precursor. When hexadecane was added into the aforementioned solvent, the synthesis became a two-phase interfacial reaction due to the large difference in solvent polarity, thereby retarding the reaction kinetics and promoting the formation of the icosahedra with the composition similar to the cubes. When evaluated as catalysts towards methanol oxidation, the Ru decorated Pt icosahedra showed much better performance in terms of specific and mass activity relative to the corresponding cubes. Specifically, the Ru decorated Pt bimetallic icosahedra achieved a specific activity of 0.76 mA cm−2 and mass activity of 74.43 mA mgPt−1, which is ∼6.7 and 2.2 times as high as those of the carbon supported Pt7Ru nanoparticles, respectively. This enhancement can be attributed to a combination of twin-induced strain and facet effects.
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高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2017
·
IF 9.446
Jibo Liu,Huijie Shi,Qi Shen,Chenyan Guo,Guohua Zhao
Aiming at improving the efficiency of photoelectrocatalytic (PEC) CO 2 conversion to methanol, a heterogeneous photoelectrocatalyst was prepared by covalently binding a Ru(II) metal-organic complex (Ru-Py) containing exposed pyridyl on the periodic TiO 2 nanotube arrays (TNTAs). PEC characterization indicated that the Ru-Py/TNTAs photocathode exhibited excellent PEC CO 2 reduction activity in aqueous solution. The initial CO 2 reduction potential on Ru-Py/TNTAs photocathode reached −0.4 V (vs. NHE) under simulated solar irradiation. The cathodic photocurrent response of Ru-Py/TNTAs in CO 2 -satuarated aqueous solution was about 1.79 mAcm −2 , which was 2.4 times that of TNTAs . It may be caused by the enhanced light absorption in the visible region originated from Ru-Py. Meanwhile, Ru-Py played an important role in accelerating the separation of photoinduced electron-hole pairs evidenced by the photoluminescence spectra. PEC CO 2 reduction test showed that 84.8 μmol methanol was produced with 63.9% faraday efficiency, 62.6 turnover number (TON) and 45% selectivity at −0.9 V under 8 h irradiation. Furthermore, the non-covalent bonded system only produced 41.3 μmol methanol indicating that the carboxylic covalent linking displayed excellent electron transfer efficiency and methanolization performance. The mechanism investigation revealed that the exposed pyridyl provided the active sites in forming pyridiniumformate intermediates confirmed by the differential UV–vis absorption ( ΔA ) spectrum, which was of great significance in the efficient CO 2 methanolization. The probable reaction pathway for catalytic CO 2 reduction to methanol was also proposed combining the possible intermediates detected by gas chromatography mass spectrometry (GCMS).
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ChemSusChem
·
2017
·Vol. 10
·期 8
·1720-1732
·
IF 7.226
Zuojun Wei,Jiongtao Lou,Chuanmin Su,Dechao Guo,Yingxin Liu,Shuguang Deng
Graphical Stability through doping : The embedding of Ru nanoparticles in N-doped mesoporous carbon effectively improve the dispersion and decrease the average size of the Ru nanoparticles, improve the adsorption of levulinic acid, and increase the interaction between Ru and the support. The strategy prevents the Ru nanoparticles from migration, aggregation, and leaching, and consequently increases the reusability of the catalyst. To achieve a higher activity and reusability of a Ru-based catalyst, Ru nanoparticles were embedded in N-doped mesoporous carbon through a hard-template method. The catalyst showed excellent catalytic performance (314 h −1 turnover frequency) and recyclability (reusable five times with 3 % activity loss) for the hydrogenolysis of levulinic acid to γ-valerolactone. Compared with the mesoporous carbon without N-doping and conventional activated carbon, the introduction of N-dopant effectively improved the dispersion of Ru nanoparticles, decreased the average size of Ru nanoparticles to as small as 1.32 nm, and improved the adsorption of levulinic acid, which contributed to the increase in the activity of the catalyst. Additionally, the embedding method increased the interaction between Ru nanoparticles and carbon support in contrast with the conventional impregnation method, thus preventing the Ru nanoparticles from migration, aggregation, and leaching from the carbon surface and therefore increasing the reusability of the catalyst.
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RSC Advances
·
2016
·Vol. 6
·期 84
·81310-81317
·
IF 3.289
Yue Liu,Lu Li,Shiwei Liu,Congxia Xie,Shitao Yu
(3-Aminopropyl)-triethoxysilane (APTS) and (3-mercaptopropyl)-trimethoxysilane (MPTS) grafted SiO2-coated iron oxide (Fe3O4@SiO2) magnetic supports were prepared. Various noble metal nanoparticles such as Ru, Pt, Rh and Pd were directly grown on the surfaces of the magnetic supports with ultrasmall and nearly monodisperse sizes, especially the APTS grafted Fe3O4@SiO2 (Fe3O4@SiO2/APTS) nanospheres. The Fe3O4@SiO2/APTS/Ru catalyst demonstrated a high catalytic activity towards the hydrogenation of α-pinene to form cis-pinane. The conversion of α-pinene was 99.1% and the selectivity for cis-pinane reached 97.6% at 120 °C after 4 h. The Fe3O4@SiO2/APTS/Ru catalyst was easily separated from the reaction mixture when applying an external magnetic field, and the separated Fe3O4@SiO2/APTS/Ru had good reusability. After being reused eight times, the α-pinene conversion and the cis-pinane selectivity also can reach 97.8% and 96.9%, respectively.
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ACS Sustainable Chemistry & Engineering
·
2017
·
IF 5.951
Wei Lv,Zhan Si,Zhipeng Tian,Chenguang Wang,Qi Zhang,Ying Xu,Tiejun Wang,Longlong Ma
An EtOAc/H2O biphasic solvent–Ru/C coupling biorefinery process was developed to selectively produce aromatics from cornstalk hydrolysis residue (CHR). In this process, CHR was depolymerized in an ethyl acetate (EtOAc)/H2O biphasic solvent system over Ru/C catalyst, which produced aromatics and carbohydrates instantly separated by EtOAc and H2O. Most lignin in CHR was converted to aromatics and nonvolatile fractions, accompanied with partial degradation of cellulose. Optimized results showed that more than 42.7% of aromatics can be obtained under 260 °C for 5 h without external hydrogen pressure. Monophasic and biphasic parallel experimental results show that the strong lignin dissolving ability of the biphasic dissolution/separation system is helpful for aromatics production and separation, which promoted CHR depolymerization over Ru/C. Furthermore, CHR, products, depolymeirzation residue solid (DRS), and catalysts were carefully characterized by gas chromatography (GC-MS), Fourier transform infrared (FT-IR), gel permeation chromatrography (GPC), high-performance liquid chromatrography mass spectrometry (HPLC-MS), nuclear magnetic resonance (NMR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis. Results demonstrated that the biphasic solvent–Ru/C coupling process can significantly alleviate repolymerization reactions. Based on these analysis results, the catalytic process in biphasic EtOAc/H2O was discussed. This work demonstrates that such a green biphasic catalytic/separation coupling system highlights a promising route for efficient biomass degradation and product separation at mild conditions without external hydrogen pressure.
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ADVANCED FUNCTIONAL MATERIALS
·
2024
·
IF 18.5
Junge Yang,Jinxian Feng,Youpeng Cao,Yuxuan Xiao,Lulu Qiao,Keyu An,Jiao Yang,Jing Peng,Hui Pan,Hui-Ming Cheng
An efficient and stable electrocatalyst is key for the production of green hydrogen using water electrolysis. However, the weak dissociation ability of Pt-based catalysts, resulting in slow kinetics severely hampers its applications in alkali medium. Herein, a simple “coincident reduction” strategy is reported to grow highly dispersed Ru-Pt heterogeneous bimetallic nanoparticles on reduced graphene oxide (Ru x Pt y @rGO) for efficient pH-universal hydrogen evolution. Ru x Pt y @rGO has superior catalytic activity at all pH values due to the synergistic effect between Ru and Pt and the ultra-small nanoparticle. In particular, the catalyst with 13.6 wt% of noble metal (Ru 1 Pt 2 @rGO) has low overpotentials of 9, 6, and 36 mV at 10 mA cm −2 in 1 m KOH, 0.5 m H 2 SO 4 and 1 m phosphate buffer solution (PBS), respectively, which outperformances monometallic counterparts and comparable to the best bimetallic catalysts ever reported. The catalyst is highly stable because of the strong bonding between the bimetallic nanoparticle and rGO. Mechanism studies show that Ru 1 Pt 2 @rGO has a faster Volmer–Tafel mechanism in alkali, high-efficient H + transfer and increased H adsorption ability in acid, resulting in superior reaction kinetics. This work provides a new route for mass production of high-performance catalysts for practical applications at all pH values.
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