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The stabilization effect of Al2sub>O3sub> on unconventional Pb/SiO2sub> catalyst

《化学科学与工程前沿（英文）》 2023年第17卷第10期页码 1423-1429 doi: 10.1007/s11705-023-2315-y

摘要： Similar to Sn, Pb located at the same group (IVA) in the periodic table of elements, can also catalyze propane dehydrogenation to propene, while a fast deactivation can be observed. To enhance the stability, the traditional carrier Al₂O₃ with a small amount, was introduced into Pb/SiO₂ catalyst in this study. It has been proved that Al₂O₃ can inhibit the reduction of PbO, and weaken the agglomeration and loss of Pb species due to its enhanced interaction with Pb species. As a result, 3Al15Pb/SiO₂ catalyst exhibits a much higher stability up to more than 150 h. In addition, a simple schematic diagram of the change of surface species on the catalyst surface after Al₂O₃ addition was also proposed.

关键词： Pb/SiO₂ Al₂O₃ propane dehydrogenation propene stability

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SiO2sub> passivation layer grown by liquid phase deposition for silicon solar cell application

Yanlin CHEN,Sihua ZHONG,Miao TAN,Wenzhong SHEN

《能源前沿（英文）》 2017年第11卷第1期页码 52-59 doi: 10.1007/s11708-016-0429-3

摘要： Surface passivation is one of the primary requirements for high efficient silicon solar cells. Though the current existed passivation techniques are effective, expensive equipments are required. In this paper, a comprehensive understanding of the SiO passivation layer grown by liquid phase deposition (LPD) was presented, which was cost-effective and very simple. It was found that the post-annealing process could significantly enhance the passivation effect of the LPD SiO film. Besides, it was revealed that both chemical passivation and field-effect passivation mechanisms played important roles in outstanding passivation effect of the LPD SiO film through analyzing the minority carrier lifetime and the surface recombination velocity of n-type and p-type silicon wafers. Although the deposition parameters had little influence on the passivation effect, they affected the deposition rate. Therefore, appropriate deposition parameters should be carefully chosen based on the compromise of the deposition rate and fabrication cost. By utilizing the LPD SiO film as surface passivation layer, a 19.5%-efficient silicon solar cell on a large-scale wafer (156 mm × 156 mm) was fabricated.

关键词： Si solar cell passivation SiO₂ liquid phase deposition carrier lifetime

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Synthesis of magnetic Pb/Fe

Hualiang AN, Xinqiang ZHAO, Zhiguang JIA, Changcheng WU, Yanji WANG

《化学科学与工程前沿（英文）》 2009年第3卷第2期页码 215-218 doi: 10.1007/s11705-009-0055-2

摘要： To facilitate the recovery of Pb/SiO catalyst, magnetic Pb/Fe O /SiO samples were prepared separately by emulsification, sol-gel and incipient impregnation methods. The catalyst samples were characterized by means of X-ray diffraction and N adsorption-desorption, and their catalytic activity was investigated in the reaction for synthesizing propylene carbonate from urea and 1,2-propylene glycol. When the gelatin was applied in the preparation of Fe O at 60°C and the pH value was controlled at 4 in the preparation of Fe O /SiO , the Pb/Fe O /SiO sample shows good catalytic activity and magnetism. Under the reaction conditions of a reaction temperature of 180°C, reaction time of 2 h, catalyst percentage of 1.7 wt-% and a molar ratio of urea to PG of 1∶4, the yield of propylene carbonate attained was 87.7%.

关键词： Pb/Fe₃O₄/SiO₂ magnetic particle urea 1 2-propylene glycol propylene carbonate

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Effect of SiO

Qian WANG, Lei WANG, Hui WANG, Zengxi LI, Xiangping ZHANG, Suojiang ZHANG, Kebin ZHOU

《化学科学与工程前沿（英文）》 2011年第5卷第1期页码 79-88 doi: 10.1007/s11705-010-0550-5

摘要： A series of SAPO-34 molecular sieves with different SiO /Al O ratios have been synthesized for the methanol-to-olefin (MTO) reaction. Their physico-chemical properties are characterized by various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR) and N adsorption-desorption. The results are compared with those of the commercial HZSM-5, which show that the crystallinity and particle diameter of SAPO-34 as well as HZSM-5 increase with SiO /Al O ratio. The variation of BET surface area of SAPO-34 is different from that of HZSM-5 and the sample with SiO /Al O ratio of 0.4 exhibits the highest BET surface area. FT-IR spectra indicate that HZSM-5 has both Br?nsted and Lewis acid sites and Br?nsted acid sites are stronger, whereas SAPO-34 samples are dominated only by Lewis acid sites. When the SiO /Al O ratio increases, propylene and butylenes become the predominant product of the MTO reaction over HZSM-5. In contrast, the main products of this reaction catalyzed by SAPO-34 are ethylene and propylene. According to the product distribution, the reaction mechanism over HZSM-5 catalysts is proposed.

关键词： HZSM-5 SAPO-34 methanol-to-olefin (MTO) SiO₂/Al₂O₃ ratio

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Influence of surface modified mixed metal oxide nanoparticles on the electrochemical and mechanical properties of polyurethane matrix

《化学科学与工程前沿（英文）》 2023年第17卷第1期页码 1-14 doi: 10.1007/s11705-022-2176-9

摘要： Newly synthesized functional nanoparticles, 3-amino-1,2,4-triazole (ATA)/SiO₂–TiO₂ were introduced to the polyurethane (PU) matrix. Electrochemical techniques were used to investigate the barrier properties of the synthesized PU–ATA/SiO₂–TiO₂ nanocomposite coated steel specimen. In natural seawater, electrochemical impedance spectroscopy experiments indicated outstanding protective behaviour for the PU–ATA/SiO₂–TiO₂ coated steel. The coating resistance (R_coat) of PU–ATA/SiO₂–TiO₂ was determined to be 2956.90 kΩ·cm^–2. The R_coat of the PU–ATA/SiO₂–TiO₂ nanocomposite coating was found to be over 50% higher than the PU coating. The current measured along the scratched surface of the PU–ATA/SiO₂–TiO₂ coating was found to be very low (1.65 nA). The enhanced ATA/SiO₂–TiO₂ nanoparticles inhibited the entry of electrolytes into the coating interface, as revealed by scanning electron microscopy/energy dispersive X-ray spectroscopy and X-ray diffraction analysis of the degradation products. Water contact angle testing validated the hydrophobic nature of the PU–ATA/SiO₂–TiO₂ coating (θ = 115.4°). When the concentration of ATA/SiO₂−TiO₂ nanoparticles was 2 wt %, dynamic mechanical analysis revealed better mechanical properties. Therefore, the newly synthesised PU–ATA/SiO₂–TiO₂ nanocomposite provided excellent barrier and mechanical properties due to the addition of ATA/SiO₂–TiO₂ nanoparticles to the polyurethane, which inhibited material degradation and aided in the prolongation of the coated steel’s life.

关键词： SiO₂/TiO₂ nanoparticle nanocomposite coatings dynamic mechanical analysis electrochemical techniques corrosion colloids and interfaces

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Theoretical and experimental study on the fluidity performance of hard-to-fluidize carbon nanotubes-based CO2

《化学科学与工程前沿（英文）》 2022年第16卷第10期页码 1460-1475 doi: 10.1007/s11705-022-2159-x

摘要： Carbon nanotubes-based materials have been identified as promising sorbents for efficient CO₂ capture in fluidized beds, suffering from insufficient contact with CO₂ for the high-level CO₂ capture capacity. This study focuses on promoting the fluidizability of hard-to-fluidize pure and synthesized silica-coated amine-functionalized carbon nanotubes. The novel synthesized sorbent presents a superior sorption capacity of about 25 times higher than pure carbon nanotubes during 5 consecutive adsorption/regeneration cycles. The low-cost fluidizable-SiO₂ nanoparticles are used as assistant material to improve the fluidity of carbon nanotubes-based sorbents. Results reveal that a minimum amount of 7.5 and 5 wt% SiO₂ nanoparticles are required to achieve an agglomerate particulate fluidization behavior for pure and synthesized carbon nanotubes, respectively. Pure carbon nanotubes + 7.5 wt% SiO₂ and synthesized carbon nanotubes + 5 wt% SiO₂ indicates an agglomerate particulate fluidization characteristic, including the high-level bed expansion ratio, low minimum fluidization velocity (1.5 and 1.6 cm·s^–1), high Richardson−Zakin index (5.2 and 5.3 > 5), and low Π value (83.2 and 84.8 < 100, respectively). Chemical modification of carbon nanotubes causes not only enhanced CO ₂ uptake capacity but also decreases the required amount of silica additive to reach a homogeneous fluidization behavior for synthesized carbon nanotubes sorbent.

关键词： CO₂ capture CNT-based sorbents fluidization SiO₂ nanoparticles fluidized bed reactors

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Preparation of P

Wenjiang LI, Fei XIE, Dongxu HUA, Chunli ZHANG, Chen DAI, Zhenyun YU, Meizhou QI, Shaojun YU

《化学科学与工程前沿（英文）》 2011年第5卷第3期页码 314-317 doi: 10.1007/s11705-010-0573-y

摘要： Silica hollow microspheres containing phosphorous have been prepared by a sol-gel/emulsion method which uses tetraethoxysilane (TEOS) as the precursor for the SiO and phosphoric acid (H PO ) as the precursor for P O . The hollow structure forms an emulsion system which is composed of an oil phase (kerosene, sorbitan monooleate (Span 80)) and an aqueous phase (a viscous sol solution of ethanol, TEOS and H PO ). Some of the phosphorous remains in the final silica shell structure even after calcination at 650°C. The hollow structure of the P O -SiO (silicophosphate) was characterized by X-ray diffraction (XRD), polarized optical microscopy (POM), scanning electron microscopy (SEM), nitrogen adsorption measurement and Fourier transform infrared spectroscopy (FTIR).

关键词： P₂O₅-SiO₂ hollow microspheres sol-gel/emulsion phosphoric acid

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Inexpensive synthesis of a high-performance Fe

Nadir Abbas, Godlisten N. Shao, Syed M. Imran, Muhammad S. Haider, Hee Taik Kim

《化学科学与工程前沿（英文）》 2016年第10卷第3期页码 405-416 doi: 10.1007/s11705-016-1579-x

摘要： A sol-gel technique has been developed for the synthesis of a magnetite-silica-titania (Fe O -SiO -TiO ) tertiary nanocomposite with improved photocatalytic properties based on the use of inexpensive titania and silica precursors. The exceptional photocatalytic activity of the resulting materials was demonstrated by using them to photocatalyze the degradation of methylene blue solution. The best formulation achieved 98% methylene blue degradation. An interesting feature of the present work was the ability to magnetically separate and reuse the catalyst. The efficiency of the catalyst remained high during two reuses. The synthesized nanomaterials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, ultra-violet-visible spectroscopy, diffuse reflectance spectroscopy, and thermogravimetric analysis. XRD analysis revealed the formation of multicrystalline systems of cubic magnetite and anatase titania crystals. SEM and TEM characterization revealed well-developed and homogeneously dispersed particles of size less than 15 nm. FTIR spectra confirmed the chemical interaction of titania and silica. It was further noticed that the optical properties of the prepared materials were dependent on the relative contents of their constituent metal oxides.

关键词： sol-gel photocatalysis magnetic recovery TiO₂ Fe₃O₄ SiO₂

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Stability of Ni/SiO

Bettina Stolze,Juliane Titus,Stephan A. Schunk,Andrian Milanov,Ekkehard Schwab,Roger Gläser

《化学科学与工程前沿（英文）》 2016年第10卷第2期页码 281-293 doi: 10.1007/s11705-016-1568-0

摘要： Ni/SiO -ZrO catalysts with Ni loadings of 1 to 13 wt-% were prepared, characterized by elemental analysis, X-ray diffraction, N sorption, temperature programmed oxidation, temperature programmed reduction, and tested for their activity and stability in the dry reforming of methane with carbon dioxide at 850 °C, gas hourly space velocity of 6000 and 1800 h and atmospheric pressure. The SiO -ZrO support as obtained through a simple and efficient sol-gel synthesis is highly porous ( = 90 m ·g , = 4.4 nm) with a homogeneously distributed Si-content of 3 wt-%. No loss of Si or formation of monoclinic ZrO , even after steaming at 850 °C for 160 h, was detectable. The catalyst with 5 wt-% Ni loading in its fully reduced state is stable over 15?h on-stream in the dry reforming reaction. If the catalyst was not fully reduced, a reduction during the early stages of dry reforming is accompanied by the deposition of up to 44 mg·g carbon as shown by experiments in a magnetic suspension balance. Rapid coking occurs for increased residence times and times-on-stream starting at 50 h. The Ni loading of 5 wt-% on SiO -ZrO was shown to provide an optimal balance between activity and coking tendency.

关键词： Ni/SiO₂-ZrO₂ synthesis gas dry reforming coking steaming

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Li4sub>SiO4sub>-coated LiNi0.5sub>Mn1.5sub>O4sub> as the high performance

Shifeng YANG, Wenfeng REN, Jian CHEN

《能源前沿（英文）》 2017年第11卷第3期页码 374-382 doi: 10.1007/s11708-017-0494-2

摘要： The preparation of Li SiO -coated LiNi Mn O materials by sintering the SiO -coated nickel-manganese oxides with lithium salts using abundant and low-cost sodium silicate as the silicon source was reported. The samples were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. It was found that a uniform and complete SiO coating layer could be obtained at a suitable pH value of 10, which transformed to a good Li SiO coating layer afterwards. When used as the cathode materials for lithium-ion batteries, the Li SiO -coated LiNi Mn O samples deliver a better electrochemical performance in terms of the discharge capacity, rate capability, and cycling stability than that of the pristine material. It can still deliver 111.1 mAh/g at 20 C after 300 cycles, with a retention ratio of 93.1% of the stable capacity, which is far beyond that of the pristine material (101.3 mAh/g, 85.6%).

关键词： lithium-ion batteries cathode material LiNi_0.5Mn_1.5O₄ lithium-ion conductor coating

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基于LiNbO3sub>/SiO2sub>/SiC异质结构实现44 GHz超高频声表面波谐振器 Article

周剑, 张定红, 刘炀辉, 卓凤玲, 钱莉荣, 李红浪, 傅永庆, 段辉高

《工程（英文）》 2023年第20卷第1期页码 112-119 doi: 10.1016/j.eng.2022.05.003

摘要：针对上述关键问题，本文提出将极端纳米制造技术与LiNbO3sub>/SiO2sub>/SiC异质结构衬底相结合的策略，成功制备出波长为160 nm的超高频SAW器件，其高阶模态谐振频率高达约基于LiNbO3sub>/SiO2sub>/SiC 异质结构衬底的超高频SAW呈现出多种模态，理论仿真分析确定了高阶声波模态的波模态。进行了超高频SAW微质量传感应用研究，其最高质量灵敏度高达33151.9 MHz⋅mm²⋅μg⁻¹，比频率为978 MHz

关键词：超高频声表面波高阶声波模态高灵敏度

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Effect of thermal pretreatment on the surface structure of PtSn/SiO

Guozhen Xu, Jian Zhang, Shengping Wang, Yujun Zhao, Xinbin Ma

《化学科学与工程前沿（英文）》 2016年第10卷第3期页码 417-424 doi: 10.1007/s11705-016-1583-1

摘要： The effect of thermal pretreatment on the active sites and catalytic performances of PtSn/SiO catalyst in acetic acid (AcOH) hydrogenation was investigated in this article. The catalysts were characterized by N physical adsorption, X-ray diffraction, transmission electron microscopy, pyridine Fourier-transform infrared spectra, and H -O titration on its physicochemical properties. The results showed that Pt species were formed primarily in crystalline structure and no PtSn alloy was observed. Meanwhile, with the increment of thermal pretreatment temperature, Pt dispersion showed a decreasing trend due to the aggregation of Pt particles. Simultaneously, the amount of Lewis acid sites was remarkably influenced by such thermal pretreatment owning to the consequent physicochemical property variation of Sn species. Interestingly, the catalytic activity showed the similar variation trend with that of Lewis acid sites, confirming the important roles of Lewis acid sites in AcOH hydrogenation. Moreover, a balancing effect between exposed Pt and Lewis acid sites was obtained, resulting in the superior catalytic performance in AcOH hydrogenation.

关键词： thermal pretreatment acetic acid hydrogenation ethanol PtSn/SiO₂

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Rh2sub>O3sub>/hexagonal CePO4sub> nanocatalysts for N2sub>O decomposition

Huan Liu, Zhen Ma

《化学科学与工程前沿（英文）》 2017年第11卷第4期页码 586-593 doi: 10.1007/s11705-017-1659-6

摘要： Hexagonal CePO nanorods were prepared by a precipitation method and hexagonal CePO nanowires were prepared by hydrothermal synthesis at 150 °C. Rh(NO ) was then used as a precursor for the impregnation of Rh O onto these CePO materials. The Rh O supported on the CePO nanowires was much more active for the catalytic decomposition of N O than the Rh O supported on CePO nanorods. The stability of both catalysts as a function of time on stream was studied and the influence of the co-feed (CO , O , H O or O /H O) on the N O decomposition was also investigated. The samples were characterized by N adsorption-desorption, inductively coupled plasma optical emission spectroscopy, X-ray diffraction, transmission electron microscopy, X-ray photoelectron microscopy, hydrogen temperature-programmed reduction, oxygen temperature-programmed desorption, and CO temperature-programmed desorption in order to correlate the physicochemical and catalytic properties.

关键词： Rh₂O₃ CePO₄ N₂O decomposition

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CO2sub> methanation and co-methanation of CO and CO2sub> over Mn-promoted Ni/Al2sub>O3sub> catalysts

Kechao Zhao,Zhenhua Li,Li Bian

《化学科学与工程前沿（英文）》 2016年第10卷第2期页码 273-280 doi: 10.1007/s11705-016-1563-5

摘要： A series of Mn-promoted 15 wt-% Ni/Al O catalysts were prepared by an incipient wetness impregnation method. The effect of the Mn content on the activity of the Ni/Al O catalysts for CO methanation and the co-methanation of CO and CO in a fixed-bed reactor was investigated. The catalysts were characterized by N physisorption, hydrogen temperature-programmed reduction and desorption, carbon dioxide temperature-programmed desorption, X-ray diffraction and high-resolution transmission electron microscopy. The presence of Mn increased the number of CO adsorption sites and inhibited Ni particle agglomeration due to improved Ni dispersion and weakened interactions between the nickel species and the support. The Mn-promoted 15 wt-% Ni/Al O catalysts had improved CO methanation activity especially at low temperatures (250 to 400 °C). The Mn content was varied from 0.86% to 2.54% and the best CO conversion was achieved with the 1.71Mn-Ni/Al O catalyst. The co-methanation tests on the 1.71Mn-Ni/Al O catalyst indicated that adding Mn markedly enhanced the CO methanation activity especially at low temperatures but it had little influence on the CO methanation performance. CO methanation was more sensitive to the reaction temperature and the space velocity than the CO methanation in the co-methanation process.

关键词： Mn promotion nickel catalysts CO₂ methanation co-methanation of CO and CO₂

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以净零排放为目标的封存驱动型CO2sub>提高采收率方法 Article

刘月亮, 芮振华

《工程（英文）》 2022年第18卷第11期页码 79-87 doi: 10.1016/j.eng.2022.02.010

摘要：可通过驱油过程将CO2sub>封存在油藏地质体中，因此，CO2sub>驱油与封存被视为降低CO2sub>排放的重要手段之一。本研究提出了一种新型的CO2sub>提高采收率（EOR）方法，即封存驱动型CO2sub>提高采收率，其主要目标是通过在油藏中封存尽可能多的CO2sub>来实现CO结果表明，DME可提高CO2sub>在原油中的溶解度，有利于CO2sub>的溶解封存；可抑制因CO2sub>的抽提作用造成的原油轻质组分“逃逸&rdquo封存驱动型CO2sub> EOR方法在提高波及效率方面优于传统的CO2sub> EOR，尤其是在采油后期更为明显；同时，封存驱动型CO2sub> EOR比传统的此外，通过封存驱动型CO2sub> EOR封存的CO2sub>量远超采出原油燃烧产生的碳排放总量。

关键词： CO2sub> EOR CO2sub>净排放量二甲醚封存驱动型CO2sub> EOR CO2sub>封存