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An investigation of the CHOH and CO selectivity of CO hydrogenation over Cu–Ce–Zr catalysts

《化学科学与工程前沿(英文)》 2022年 第16卷 第6期   页码 950-962 doi: 10.1007/s11705-022-2162-2

摘要: A series of Cu–Ce–Zr catalysts with different Ce contents are applied to the hydrogenation of CO2 to CO/CH3OH products. The Cu–Ce–Zr catalyst with 2 wt% Ce loading shows higher CO selectivity (SCO = 0.0%–87.8%) from 200–300 °C, while the Cu–Ce–Zr catalyst with 8 wt% Ce loading presents higher CO2 conversion ( XCO2 = 5.4%–15.6%) and CH3OH selectivity ( SCH3OH = 97.8%–40.6%). The number of hydroxyl groups and solid solution nature play a significant role in changing the reaction pathway. The solid solution enhances the CO2 adsorption ability. At the CO2 adsorption step, a larger number of hydroxyl groups over the Cu–Ce–Zr catalyst with 8 wt% Ce loading leads to the production of H-containing adsorption species. At the CO2 hydrogenation step, a larger number of hydroxyl groups assists in encouraging the further hydrogenation of intermediate species to CH3OH and improving the hydrogenation rate. Hence, the Cu–Ce–Zr catalyst with 8 wt% Ce loading favors CH3OH selectivity and CO2 activation, while CO is preferred on the Cu–Ce–Zr catalyst with 2 wt% Ce loading, a smaller number of hydroxyl groups and a solid solution nature. Additionally, high-pressure in situ diffuse reflectance infrared Fourier transform spectroscopy shows that CO is produced from formate decomposition and that both monodentate formate and bidentate formate are active intermediate species of CO2 hydrogenation to CH3OH.

关键词: CO2 hydrogenation     Cu–Ce–Zr     hydroxyls     CO/CH3OH selectivity    

Promoting effect of Zr on the catalytic combustion of methane over Pd/γ-Al

Hongbo NA,Tianle ZHU,Zhiming LIU,Yifei SUN

《环境科学与工程前沿(英文)》 2014年 第8卷 第5期   页码 659-665 doi: 10.1007/s11783-013-0613-1

摘要: The effect of Zr on the catalytic performance of Pd/γ-Al O for the methane combustion was investigated. The results show that the addition of Zr can improve the activity and stability of Pd/γ-Al O catalyst, which, based on the catalyst characterization (N adsorption, XRD, CO-Chemisorption, XPS, CH -TPR and O -TPO), is ascribed to the interaction between Pd and Zr. The active phase of methane combustion over supported palladium catalyst is the Pd /Pd mixture. Zr addition inhibits Pd aggregation and enhances the redox properties of active phase Pd / Pd . H reduction could effectively reduce the oxidation degree of Pd species and regenerate the active sites (Pd / Pd ).

关键词: Pd-Zr/Al2O3     methane     catalytic combustion     catalyst regeneration    

PM-support interfacial effect and oxygen mobility in Pt, Pd or Rh-loaded (Ce,Zr,La)O catalysts

《环境科学与工程前沿(英文)》 2021年 第15卷 第4期 doi: 10.1007/s11783-020-1369-z

摘要:

• Pt/CZL exhibits the optimum catalytic performance for HC and NOx elimination.

关键词: Precious metal-loaded (Ce     Zr     La)O2 catalysts     Oxygen mobility     Catalytic performance    

Research progress of defect-engineered UiO-66(Zr) MOFs for photocatalytic hydrogen production

《能源前沿(英文)》 2021年 第15卷 第3期   页码 656-666 doi: 10.1007/s11708-021-0765-9

摘要: In recent years, defect-engineered Zr-based UiO-66 metal-organic frameworks (UiO-66(Zr) metal-organic frameworks (MOFs)) have shown huge advantages in catalytic, functional materials, adsorption, and other fields due to their large surface areas, well-ordered porous structures, and flexible tailorability. It is extremely challenging to introduce defect sites in the synthesis of MOFs to regulate the physicochemical properties of materials such as (energy band structure, pore structure, etc.) to obtain an excellent performance. This paper reviews the recent research results of synthesis methods, characterization technologies, and application fields of defect-engineered UiO-66(Zr) MOFs materials in order to provide new insights to synthesize high-performance UiO-66(Zr) MOFs materials and promote the development of UiO-66(Zr) in various fields.

关键词: defect engineering     metal-organic frameworks     UiO-66     photocatalysis    

Tailoring the simultaneous abatement of methanol and NO on Sb-Ce-Zr catalysts via copper modification

《环境科学与工程前沿(英文)》 2022年 第16卷 第10期 doi: 10.1007/s11684-022-1565-0

摘要:

● Cu addition enhances CH3OH oxidation and alleviates its inhibitory effect on SCR.

关键词: Copper modification     Sb-CeZr2Ox catalyst     NOx     Methanol     Simultaneous removal    

Oxidation-extraction desulfurization of model oil over Zr-ZSM-5/SBA-15 and kinetic study

Chuanzhu LU,Hui FU,Huipeng LI,Hua ZHAO,Tianfeng CAI

《化学科学与工程前沿(英文)》 2014年 第8卷 第2期   页码 203-211 doi: 10.1007/s11705-014-1420-3

摘要: ZSM-5/SBA-15 composite molecular sieves were synthesized using post-synthesis method and characterized by X-ray diffraction and N adsorption-desorption. The oxidative-extration desulfurization of model oil was investigated by using hydrogen peroxide as the oxidant, tetrabutyl ammonium bromide as phase transfer catalyst, dimethyl sulfoxide as extractant, and Zr-ZSM-5/SBA-15, Ag-ZSM-5/SBA-15, Ce-ZSM-5/SBA-15 as catalyst. Under the optimal conditions, the desulfurization rate decreases in the order: Zr-ZSM-5/SBA-15>Ce-ZSM-5/SBA-15>Ag-ZSM-5/SBA-15. The highest desulfurization rate is 84.53% under the catalysis of Zr-ZSM-5/SBA-15. Kinetics analysis shows that the reaction is pseudo-first-order with the activation energy of 44.23 kJ/mol.

关键词: composite molecular sieve     oxidation desulfuration     extraction     kinetic    

Ultrafine Fe-modulated Ni nanoparticles embedded within nitrogen-doped carbon from Zr-MOFs-confined conversion

《化学科学与工程前沿(英文)》 2022年 第16卷 第7期   页码 1114-1124 doi: 10.1007/s11705-021-2087-1

摘要: Improvement of the low-cost transition metal electrocatalyst used in sluggish oxygen evolution reaction is a significant but challenging problem. In this study, ultrafine Fe-modulated Ni nanoparticles embedded in a porous Ni-doped carbon matrix were produced by the pyrolysis of zirconium metal-organic-frameworks, in which 2,2′-bipyridine-5,5′-dicarboxylate operating as a ligand can coordinate with Ni2+ and Fe3+. This strategy allows formation of Fe-modulated Ni nanoparticles with a uniform dimension of about 2 nm which can be ascribed to the spatial blocking effect of ZrO2. This unique catalyst displays an efficient oxygen evolution reaction electrocatalytic activity with a low overpotential of 372 mV at 10 mA·cm–2 and a small Tafel slope of 84.4 mV·dec–1 in alkaline media. More importantly, it shows superior durability and structural stability after 43 h in a chronoamperometry test. Meanwhile, it shows excellent cycling stability during 4000 cyclic voltammetry cycles. This research offers a new insight into the construction of uniform nanoscale transition metals and their alloys as highly efficient and durable electrocatalysts.

关键词: metal-organic framework     pyrolysis     ultrafine     Fe-modulated Ni nanoparticles     oxygen evolution reaction    

Promotion of transition metal oxides on the NH

Weiman Li, Haidi Liu, Yunfa Chen

《环境科学与工程前沿(英文)》 2017年 第11卷 第2期 doi: 10.1007/s11783-017-0914-x

摘要: Manganese and chromium oxides promote the NH -SCR activity of Zr-Ce mixed oxide. Cr-Zr-Ce mixed oxide exhibited>80% NO conversion at a wide temperature window. More acid sites and higher reducibility may responsible for the high SCR ability. Chromium oxide and manganese oxide promoted ZrO -CeO catalysts were prepared by a homogeneous precipitation method for the selective catalytic reduction of NO with NH . A series of characterization including X-ray diffraction (XRD), high-resolution transmission electron microscope (HR-TEM), Brunauer–Emmett–Teller (BET) surface area analysis, H temperature-programmed reduction (H -TPR), and X-ray photoelectron spectroscopy (XPS) were used to evaluate the influence of the physicochemical properties on NH -SCR activity. Cr-Zr-Ce and Mn-Zr-Ce catalysts are much more active than ZrO -CeO binary oxide for the low temperature NH -SCR, mainly because of the high specific surface area, more surface oxygen species, improved reducibility derived from synergistic effect among different elements. Mn-Zr-Ce catalyst exhibited high tolerance to SO and H O. Cr-Zr-Ce mixed oxide exhibited>80% NO conversion at a wide temperature window of 100°C–300°C. DRIFT studies showed that the addition of Cr is beneficial to the formation of Bronsted acid sites and prevents the formation of stable nitrate species because of the presence of Cr . The present mixed oxide can be a candidate for the low temperature abatement of NO .

关键词: NH3-selective catalytic reduction     NOx     Low temperature     Cr-Zr-Ce    

Zr66Al9Cu16Ni9块体非晶合金制备工艺研究

阮许平,阮宏伟

《中国工程科学》 2004年 第6卷 第5期   页码 76-78

摘要: 采用三种不同的方法对金属熔体进行处理,试样的X射线衍射晶化相分析结果表明,B2O3和Na2SiO3的混合物与所选组分的熔体发生了反应,不适合作Zr基合金的包裹物;组分为CaF2(45%),AlF3(50%),CaO(5%)以及微量的TiO2的氟盐,由于该净化剂与所选的组分发生了反应,不适合Zr

关键词: 块体非晶合金     制备工艺     玻璃     熔盐     真空度    

Cooperative effect between copper species and oxygen vacancy in CeZrCuO catalysts for carbon monoxide oxidation

《化学科学与工程前沿(英文)》 2021年 第15卷 第6期   页码 1524-1536 doi: 10.1007/s11705-021-2106-2

摘要: The effects of Zr doping on the existence of Cu and the catalytic performance of Ce0.7−xZrxCu0.3O2 for CO oxidation were investigated. The characterization results showed that all samples have a cubic structure, and a small amount of Zr doping facilitates Cu2+ ions entering the CeO2 lattice, but excessive Zr doping leads to the formation of surface CuO crystals again. Thus, the number of oxygen vacancies caused by the Cu2+ entering the lattice (e.g., Cu2+–□–Ce4+; □: oxygen vacancy), and the amount of reducible copper species caused by CuO crystals, varies with the Zr doping. Catalytic CO oxidation tests indicated that the oxygen vacancy and the reducible copper species were the adsorption and activation sites of O2 and CO, respectively, and the cooperative effects between them accounted for the high CO oxidation activity. Thus, the samples x = 0.1 and 0.3, which possessed the most oxygen vacancy or reducible copper species, showed the best activity for CO oxidation, with full CO conversion obtained at 110 °C. The catalyst is also stable and has good resistance to water during the reaction.

关键词: Ce–Zr–Cu–O     CO oxidation     reducible copper species     oxygen vacancy     cooperative effect    

Highly efficient and selective removal of phosphate from wastewater of sea cucumber aquaculture for microalgae culture using a new adsorption-membrane separation-coordinated strategy

《环境科学与工程前沿(英文)》 2023年 第17卷 第10期 doi: 10.1007/s11783-023-1720-2

摘要:

● A new adsorption-membrane separation strategy is used for phosphate removal.

关键词: Adsorption-membrane     Low-concentration phosphate     Zr-modified-bentonite     Recycle     Microalgal culture    

ZR2015QZ08)

Feng-yu ZHOU,Xian-feng YUAN,Yang YANG,Zhi-fei JIANG,Chen-lei ZHOU

《信息与电子工程前沿(英文)》 2016年 第17卷 第4期   页码 365-374 doi: 10.1631/FITEE.1500272

摘要: To overcome the shortcomings of existing robot localization sensors, such as low accuracy and poor robustness, a high precision visual localization system based on infrared-reflective artificial markers is designed and illustrated in detail in this paper. First, the hardware system of the localization sensor is developed. Secondly, we design a novel kind of infrared-reflective artificial marker whose characteristics can be extracted by the acquisition and processing of the infrared image. In addition, a confidence calculation method for marker identification is proposed to obtain the probabilistic localization results. Finally, the autonomous localization of the robot is achieved by calculating the relative pose relation between the robot and the artificial marker based on the perspective-3-point (P3P) visual localization algorithm. Numerous experiments and practical applications show that the designed localization sensor system is immune to the interferences of the illumination and observation angle changes. The precision of the sensor is ±1.94 cm for position localization and ±1.64? for angle localization. Therefore, it satisfies perfectly the requirements of localization precision for an indoor mobile robot.

关键词: Mobile robot     Localization sensor     Visual localization     Infrared-reflective marker     Embedded system    

Preparation of ceria-zirconia solid solution with enhanced oxygen storage capacity and redox performance

Lijing MENG, Licheng LIU, Xuehong ZI, Hongxing DAI, Hong HE, Zhen ZHAO, Xinping WANG,

《环境科学与工程前沿(英文)》 2010年 第4卷 第2期   页码 164-171 doi: 10.1007/s11783-010-0019-2

摘要: A new method called ultrasonic-assisted membrane reaction (UAMR) was reported for the fabrication of ceria-zirconia solid solution. A series of ceria-zirconia solid solutions with different Ce/Zr molar ratios were prepared by the UAMR method and characterized by X-ray diffraction (XRD), N adsorption, hydrogen temperature-programmed reduction (H-TPR), scanning electron microscope (SEM), and transmission electron microscopy (TEM) techniques. The UAMR method proved to be superior, especially when the Ce/Zr molar ratio was lower than 1, in fabricating ceria-zirconia solid solutions with large BET surface area, high oxygen storage capacity (OSC), and low reduction temperature.

关键词: membrane reaction     ceria-zirconia     Ce/Zr molar ratio     solid solution     hydrogen temperature-programmed reduction (H2-TPR)    

标题 作者 时间 类型 操作

An investigation of the CHOH and CO selectivity of CO hydrogenation over Cu–Ce–Zr catalysts

期刊论文

Promoting effect of Zr on the catalytic combustion of methane over Pd/γ-Al

Hongbo NA,Tianle ZHU,Zhiming LIU,Yifei SUN

期刊论文

PM-support interfacial effect and oxygen mobility in Pt, Pd or Rh-loaded (Ce,Zr,La)O catalysts

期刊论文

Research progress of defect-engineered UiO-66(Zr) MOFs for photocatalytic hydrogen production

期刊论文

Tailoring the simultaneous abatement of methanol and NO on Sb-Ce-Zr catalysts via copper modification

期刊论文

Oxidation-extraction desulfurization of model oil over Zr-ZSM-5/SBA-15 and kinetic study

Chuanzhu LU,Hui FU,Huipeng LI,Hua ZHAO,Tianfeng CAI

期刊论文

Ultrafine Fe-modulated Ni nanoparticles embedded within nitrogen-doped carbon from Zr-MOFs-confined conversion

期刊论文

Promotion of transition metal oxides on the NH

Weiman Li, Haidi Liu, Yunfa Chen

期刊论文

Zr66Al9Cu16Ni9块体非晶合金制备工艺研究

阮许平,阮宏伟

期刊论文

Cooperative effect between copper species and oxygen vacancy in CeZrCuO catalysts for carbon monoxide oxidation

期刊论文

Highly efficient and selective removal of phosphate from wastewater of sea cucumber aquaculture for microalgae culture using a new adsorption-membrane separation-coordinated strategy

期刊论文

ZR2015QZ08)

Feng-yu ZHOU,Xian-feng YUAN,Yang YANG,Zhi-fei JIANG,Chen-lei ZHOU

期刊论文

Preparation of ceria-zirconia solid solution with enhanced oxygen storage capacity and redox performance

Lijing MENG, Licheng LIU, Xuehong ZI, Hongxing DAI, Hong HE, Zhen ZHAO, Xinping WANG,

期刊论文