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Zinc modification of Ni-Ti as efficient NiZnTi catalysts with both geometric and electronic improvements for hydrogenation of nitroaromatics

《化学科学与工程前沿(英文)》 2022年 第16卷 第4期   页码 461-474 doi: 10.1007/s11705-021-2072-8

摘要: The catalytic hydrogenation of nitroaromatics is an environmentally friendly technology for aniline production, and it is crucial to develop noble-metal-free catalysts that can achieve chemoselective hydrogenation of nitroaromatics under mild reaction conditions. In this work, zinc-modified Ni-Ti catalysts (NixZnyTi1) were fabricated and applied for the hydrogenation of nitroaromatics hydrogenation. It was found that the introduction of zinc effectively increases the surface Ni density, enhances the electronic effect, and improves the interaction between Ni and TiO2, resulting in smaller Ni particle size, more oxygen vacancies, higher dispersion and greater concentration of Ni on the catalyst surface. Furthermore, the electron-rich Niδ obtained by electron transfer from Zn and Ti to Ni effectively adsorbs and dissociates hydrogen. The results reveal that NixZnyTi1 (Ni0.5Zn0.5Ti1) shows excellent catalytic performance under mild conditions (70 °C and 6 bar). These findings provide a rational strategy for the development of highly active non-noble-metal hydrogenation catalysts.

关键词: bimetal strategy     oxygen vacancy     non-noble metal catalyst     hydrogenation     aromatic nitro compounds    

Catalytic activity of noble metal nanoparticles toward hydrodechlorination: influence of catalyst electronic

Man ZHANG,Feng HE,Dongye ZHAO

《环境科学与工程前沿(英文)》 2015年 第9卷 第5期   页码 888-896 doi: 10.1007/s11783-015-0774-1

摘要: In this study, stabilized Pd, Pt and Au nanoparticles were successfully prepared in aqueous phase using sodium carboxymethyl cellulose (CMC) as a capping agent. These metal nanoparticles were then tested for catalytic hydrodechlorination toward two classes of organochlorinated compounds (vinyl polychlorides including trichloroethylene (TCE), tetrachloroethylene (PCE), and alkyl polychlorides including 1,1,1-trichloroethane (1,1,1-TCA), and 1,1,1,2-tetrachloroethane (1,1,1,2-TeCA)) to determine the rate-limiting steps and to explore the reaction mechanisms. The surface area normalized reaction rate constant, , showed a systematic dependence on the electronic structure (the density of states at the Fermi level) of the metals, suggesting that adsorption of organochlorinated reactants on the metal catalyst surfaces is the rate-limiting step for catalytic hydrodechlorination. Hydrodechlorination rates of 1,1,1-TCA and 1,1,1,2-TeCA agreed with the bond strength of the first (weakest) dissociated C-Cl bond, suggesting that C-Cl bond cleavage, which is the first step for dissociative adsorption of the alkyl polychlorides, controlled the catalytic hydrodechlorination rate. However, hydrodechlorination rates of TCE and PCE correlated with the adsorption energies of their molecular (non-dissociative) adsorption on the noble metals rather than with the first C-Cl bond strength, suggesting that molecular adsorption governs the reaction rate for hydrodechlorination of the vinyl polychlorides.

关键词: catalytic hydrodechlorination     electronic structure     metal nanoparticles     reaction mechanisms    

Hydro-pyrolysis of lignocellulosic biomass over alumina supported Platinum, Mo

Songbo He, Jeffrey Boom, Rolf van der Gaast, K. Seshan

《化学科学与工程前沿(英文)》 2018年 第12卷 第1期   页码 155-161 doi: 10.1007/s11705-017-1655-x

摘要: In-line hydro-treatment of bio-oil vapor from fast pyrolysis of lignocellulosic biomass (hydro-pyrolysis of biomass) is studied as a method of upgrading the liquefied bio-oil for a possible precursor to green fuels. The nobel metal (Pt) and non-noble metal catalysts (Mo C and WC) were compared at 500 °C and atmospheric pressure which are same as the reaction conditions for fast pyrolysis of biomass. Results indicated that under the pyrolysis conditions, the major components, such as acids and carbonyls, of the fast pyrolysis bio-oil can be completely and partially hydrogenated to form hydrocarbons, an ideal fossil fuel blend, in the hydro-treated bio-oil. The carbide catalysts perform equally well as the Pt catalyst regarding to the aliphatic and aromatic hydrocarbon formation (ca. 60%), showing the feasibility of using the cheap non-noble catalysts for hydro-pyrolysis of biomass.

关键词: bio-oil     pyrolysis     hydro-deoxygenation (HDO)     non-noble metal catalysts     hydro-treatment    

Highly uniform Ni particles with phosphorus and adjacent defects catalyze 1,5-dinitronaphthalene hydrogenation with excellent catalytic performance

Wei Xiong, Susu Zhou, Zeyong Zhao, Fang Hao, Zhihui Cai, Pingle Liu, Hailiang Zhang, Hean Luo

《化学科学与工程前沿(英文)》 2021年 第15卷 第4期   页码 998-1007 doi: 10.1007/s11705-020-1994-x

摘要: This work proposes a modified activated carbon support, with defects and heteroatoms (N,P-ACs) by nitrogen and phosphorus doping to load non-noble nickel to catalyze aromatic compound hydrogenation. The Ni/N,P-ACs-900 (prepared at 900 °C) showed promising catalytic activity in liquid-phase 1,5-dinitronaphthalene hydrogenation with a 1,5-diaminonaphthalene yield of 95.8% under the mild condition of 100 °C, which is comparable to the commercial Pd/C catalyst. The nitrogen species were burned off at 900 °C, causing more defects for nickel metal loading, facilitating the interaction between the supports and the nickel metal, and resulting in highly dispersed metal particles. The computational study of the nickel binding energy has been conducted using density functional theory. It exhibits that the defects formed by heteroatom doping are beneficial to nickel anchoring and deposition to form highly uniform nickel particles. The phosphorus species in combination with the defects are suitable for H adsorption and dissociation. These results reveal that the heteroatomic doping on the active carbon shows significant effects in the hydrogenation of the liquid-phase aromatic compounds. These findings could provide a promising route for the rational design of aromatic compound hydrogenation catalysts to significantly decrease the cost by instead using noble metal catalysts in the industry.

关键词: nitrogen and phosphorus doping     non-noble nickel catalyst     aromatic compounds hydrogenation    

Exploration of the oxygen transport behavior in non-precious metal catalyst-based cathode catalyst layer

Shiqu CHEN, Silei XIANG, Zehao TAN, Huiyuan LI, Xiaohui YAN, Jiewei YIN, Shuiyun SHEN, Junliang ZHANG

《能源前沿(英文)》 2023年 第17卷 第1期   页码 123-133 doi: 10.1007/s11708-022-0849-1

摘要: High cost has undoubtedly become the biggest obstacle to the commercialization of proton exchange membrane fuel cells (PEMFCs), in which Pt-based catalysts employed in the cathodic catalyst layer (CCL) account for the major portion of the cost. Although non-precious metal catalysts (NPMCs) show appreciable activity and stability in the oxygen reduction reaction (ORR), the performance of fuel cells based on NPMCs remains unsatisfactory compared to those using Pt-based CCL. Therefore, most studies on NPMC-based fuel cells focus on developing highly active catalysts rather than facilitating oxygen transport. In this work, the oxygen transport behavior in CCLs based on highly active Fe-N-C catalysts is comprehensively explored through the elaborate design of two types of membrane electrode structures, one containing low-Pt-based CCL and NPMC-based dummy catalyst layer (DCL) and the other containing only the NPMC-based CCL. Using Zn-N-C based DCLs of different thickness, the bulk oxygen transport resistance at the unit thickness in NPMC-based CCL was quantified via the limiting current method combined with linear fitting analysis. Then, the local and bulk resistances in NPMC-based CCLs were quantified via the limiting current method and scanning electron microscopy, respectively. Results show that the ratios of local and bulk oxygen transport resistances in NPMC-based CCL are 80% and 20%, respectively, and that an enhancement of local oxygen transport is critical to greatly improve the performance of NPMC-based PEMFCs. Furthermore, the activity of active sites per unit in NPMC-based CCLs was determined to be lower than that in the Pt-based CCL, thus explaining worse cell performance of NPMC-based membrane electrode assemblys (MEAs). It is believed that the development of NPMC-based PEMFCs should proceed not only through the design of catalysts with higher activity but also through the improvement of oxygen transport in the CCL.

关键词: proton exchange membrane fuel cells (PEMFCs)     non-precious metal catalyst (NPMC)     cathode catalyst layer (CCL)     local and bulk oxygen transport resistance    

Hollow carbon spheres and their noble metal-free hybrids in catalysis

《化学科学与工程前沿(英文)》 2021年 第15卷 第6期   页码 1380-1407 doi: 10.1007/s11705-021-2097-z

摘要: Hollow carbon spheres have garnered great interest owing to their high surface area, large surface-to-volume ratio and reduced transmission lengths. Herein, we overview hollow carbon sphere-based materials and their noble metal-free hybrids in catalysis. Firstly, we summarize the key fabrication techniques for various kinds of hollow carbon spheres, with a particular emphasis on controlling pore structure and surface morphology, and then heterogeneous doping as well as their metal-free/containing hybrids are presented; next, possible applications for non-noble metal/hollow carbon sphere hybrids in the area of energy-related catalysis, including oxygen reduction reaction, hydrogen evolution reaction, oxygen evolution reaction, water splitting, rechargeable Zn-air batteries and pollutant degradation are discussed; finally, we introduce the various challenges and opportunities offered by hollow carbon spheres from the perspective of synthesis and catalysis.

关键词: hollow carbon spheres     functionalization     noble metal-free     catalysis    

Effect of noble metal nanoparticle size on C–N bond cleavage performance in hydrodenitrogenation: a study

《化学科学与工程前沿(英文)》 2023年 第17卷 第12期   页码 1986-2000 doi: 10.1007/s11705-023-2337-5

摘要: Breakage of the C–N bond is a structure sensitive process, and the catalyst size significantly affects its activity. On the active metal nanoparticle scale, the role of catalyst size in C–N bond cleavage has not been clearly elucidated. So, Ru catalysts with variable nanoparticle sizes were obtained by modulating the reduction temperature, and the catalytic activity was evaluated using 1,2,3,4-tetrahydroquinoline and o-propylaniline with different C–N bond hybridization patterns as reactants. Results showed a 13 times higher reaction rate for sp3-hybridized C–N bond cleavage than sp2-hybridized C–N bond cleavage, while the reaction rate tended to increase first and then decrease as the catalyst nanoparticle size increased. Different concentrations of terrace, step, and corner sites were found in different sizes of Ru nanoparticles. The relationship between catalytic site variation and C–N bond cleavage activity was further investigated by calculating the turnover frequency values for each site. This analysis indicates that the variation of different sites on the catalyst is the intrinsic factor of the size dependence of C–N bond cleavage activity, and the step atoms are the active sites for the C–N bond cleavage. When Ru nanoparticles are smaller than 1.9 nm, they have a strong adsorption effect on the reactants, which will affect the catalytic performance of the Ru catalyst. Furthermore, these findings were also confirmed on other metallic Pd/Pt catalysts. The role of step sites in C–N bond cleavage was proposed using the density function theory calculations. The reactants have stronger adsorption energies on the step atoms, and step atoms have d-band center nearer to the Fermi level. In this case, the interaction with the reactant is stronger, which is beneficial for activating the C–N bond of the reactant.

关键词: sp3/sp2-hybridized C–N bond     noble metal nanoparticle     catalytic active site     turnover frequency     DFT    

Shape/size controlling syntheses, properties and applications of two-dimensional noble metal nanocrystals

Baozhen An,Mingjie Li,Jialin Wang,Chaoxu Li

《化学科学与工程前沿(英文)》 2016年 第10卷 第3期   页码 360-382 doi: 10.1007/s11705-016-1576-0

摘要: Two dimensional (2D) nanocrystals of noble metals (e.g., Au, Ag, Pt) often have unique structural and environmental properties which make them useful for applications in electronics, optics, sensors and biomedicines. In recent years, there has been a focus on discovering the fundamental mechanisms which govern the synthesis of the diverse geometries of these 2D metal nanocrystals (e.g., shapes, thickness, and lateral sizes). This has resulted in being able to better control the properties of these 2D structures for specific applications. In this review, a brief historical survey of the intrinsic anisotropic properties and quantum size effects of 2D noble metal nanocrystals is given and then a summary of synthetic approaches to control their shapes and sizes is presented. The unique properties and fascinating applications of these nanocrystals are also discussed.

关键词: two-dimension     noble metal     nanocrystal     surface plasmon     controllable synthesis    

Copper nanoparticles/polyaniline-derived mesoporous carbon electrocatalysts for hydrazine oxidation

Tao Zhang, Tewodros Asefa

《化学科学与工程前沿(英文)》 2018年 第12卷 第3期   页码 329-338 doi: 10.1007/s11705-018-1741-8

摘要:

Copper nanoparticles-decorated polyaniline-derived mesoporous carbon that can serve as noble metal-free electrocatalyst for the hydrazine oxidation reaction (HzOR) is synthesized via a facile synthetic route. The material exhibits excellent electrocatalytic activity toward HzOR with low overpotential and high current density. The material also remains stable during the electrocatalytic reaction for long time. Its good electrocatalytic performance makes this material a promising alternative to conventional noble metal-based catalysts (e.g., Pt) that are commonly used in HzOR-based fuel cells.

关键词: copper nanoparticles     mesoporous carbon     noble metal-free electrocatalyst     hydrazine oxidation reaction     polyaniline    

Diffusion process in enzyme–metal hybrid catalysts

《化学科学与工程前沿(英文)》 2022年 第16卷 第6期   页码 921-929 doi: 10.1007/s11705-022-2144-4

摘要: Enzyme–metal hybrid catalysts bridge the gap between enzymatic and heterogeneous catalysis, which is significant for expanding biocatalysis to a broader scope. Previous studies have demonstrated that the enzyme–metal hybrid catalysts exhibited considerably higher catalytic efficiency in cascade reactions, compared with that of the combination of separated enzyme and metal catalysts. However, the precise mechanism of this phenomenon remains unclear. Here, we investigated the diffusion process in enzyme–metal hybrid catalysts using Pd/lipase-Pluronic conjugates and the combination of immobilized lipase (Novozyme 435) and Pd/C as models. With reference to experimental data in previous studies, the Weisz–Prater parameter and efficiency factor of internal diffusion were calculated to evaluate the internal diffusion limitations in these catalysts. Thereafter, a kinetic model was developed and fitted to describe the proximity effect in hybrid catalysts. Results indicated that the enhanced catalytic efficiency of hybrid catalysts may arise from the decreased internal diffusion limitation, size effect of Pd clusters and proximity of the enzyme and metal active sites, which provides a theoretical foundation for the rational design of enzyme–metal hybrid catalysts.

关键词: enzyme–metal hybrid catalyst     internal diffusion     proximity effect     kinetic model    

Noble-metal-free cobalt hydroxide nanosheets for efficient electrocatalytic oxidation

Jie Lan, Daizong Qi, Jie Song, Peng Liu, Yi Liu, Yun-Xiang Pan

《化学科学与工程前沿(英文)》 2020年 第14卷 第6期   页码 948-955 doi: 10.1007/s11705-020-1920-2

摘要: Cobalt hydroxide has been emerging as a promising catalyst for the electrocatalytic oxidation reactions, including the oxygen evolution reaction (OER) and glucose oxidation reaction (GOR). Herein, we prepared cobalt hydroxide nanoparticles (CoHP) and cobalt hydroxide nanosheets (CoHS) on nickel foam. In the electrocatalytic OER, CoHS shows an overpotential of 306 mV at a current density of 10 mA·cm . This is enhanced as compared with that of CoHP (367 mV at 10 mA·cm ). In addition, CoHS also exhibits an improved performance in the electrocatalytic GOR. The improved electrocatalytic performance of CoHS could be due to the higher ability of the two-dimensional nanosheets on CoHS in electron transfer. These results are useful for fabricating efficient catalysts for electrocatalytic oxidation reactions.

关键词: electrocatalytic oxidation     cobalt hydroxide     nanosheet     water     glucose    

Micro-sized hydrothermal carbon supporting metal oxide nanoparticles as efficient catalyst for mono-dehydration

Cheng PAN, Chao FAN, Wanqin WANG, Teng LONG, Benhua HUANG, Donghua ZHANG, Peigen SU, Aqun ZHENG, Yang SUN

《能源前沿(英文)》 2022年 第16卷 第5期   页码 822-839 doi: 10.1007/s11708-020-0677-0

摘要: Most known catalytic dehydration of sugar alcohols such as D-sorbitol and D-mannitol can only produce di-dehydrated forms as major product, but mono-dehydrated products are also useful chemicals. Moreover, both di- and mono-dehydration demand a high temperature (150°C or higher), which deserves further attentions. To improve the mono-dehydration efficiency, a series of metal-containing hydrothermal carbonaceous materials (HTC) are prepared as catalyst in this work. Characterization reveals that the composition of preparative solution has a key influence on the morphology of HTC. In transformation of D-sorbitol, all HTC catalysts show low conversions in water regardless of temperature, but much better outputs are obtained in ethanol, especially at a higher temperature. When D-mannitol is selected as substrate, moderate to high conversions are obtained in both water and ethanol. On the other hand, high mono-dehydration selectivity is obtained for both sugar alcohols by using all catalysts. The origin of mono-dehydration selectivity and role of carbon component in catalysis are discussed in association with calculations. This study provides an efficient, mild, eco-friendly, and cost-effective system for mono-dehydration of sugar alcohols, which means a lot to development in new detergents or other fine chemicals.

关键词: hydrothermal carbon     morphology     catalyst     mono-dehydration     sugar alcohol    

Fischer-Tropsch synthesis by reduced graphene oxide nanosheets supported cobalt catalysts: Role of support and metalnanoparticle size on catalyst activity and products selectivity

Hasan Oliaei Torshizi, Ali Nakhaei Pour, Ali Mohammadi, Yahya Zamani, Seyed Mehdi Kamali Shahri

《化学科学与工程前沿(英文)》 2021年 第15卷 第2期   页码 299-309 doi: 10.1007/s11705-020-1925-x

摘要: In this paper, a series of cobalt catalysts supported on reduced graphene oxide (rGO) nanosheets with the loading of 5, 15 and 30 wt-% were provided by the impregnation method. The activity of the prepared catalysts is evaluated in the Fischer-Tropsch synthesis (FTS). The prepared catalysts were carefully characterized by nitrogen adsorption-desorption, hydrogen chemisorption, X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, temperature programmed reduction, transmission electron microscopy, and field emission scanning electron microscopy techniques to confirm that cobalt particles were greatly dispersed on the rGO nanosheets. The results showed that with increasing the cobalt loading on the rGO support, the carbon defects are increased and as a consequence, the reduction of cobalt is decreased. The FTS activity results showed that the cobalt-time yield and turnover frequency passed from a maximum for catalyst with the Co average particle size of 15 nm due to the synergetic effect of cobalt reducibility and particle size. The products selectivity results indicated that the methane selectivity decreases, whereas the C selectivity raises with the increasing of the cobalt particle size, which can be explained by chain propagation in the primary chain growth reactions.

关键词: cobalt catalyst     cobalt particle size     Fischer-Tropsch synthesis     reduced graphene oxide     supported catalyst    

非并网风电应用中金属材料清洗与防护技术

吴 昊,邹宜哲,白 珂

《中国工程科学》 2015年 第17卷 第3期   页码 41-44

摘要:

为了保证大规模非并网风电装备,特别是金属构件的正常使用,需要对其进行必要的清洗及预防腐处理等前处理,为后续涂层等最终防护工序打下良好材料基础。本文针对金属部件的清洗与预防腐处理技术进行了研究,研发出金属清洗与防护产品,并进行了应用研究。

关键词: 大规模非并网风电;金属;清洗;预防腐;前处理    

Recent advances on metal-free graphene-based catalysts for the production of industrial chemicals

Zhiyong Wang, Yuan Pu, Dan Wang, Jie-Xin Wang, Jian-Feng Chen

《化学科学与工程前沿(英文)》 2018年 第12卷 第4期   页码 855-866 doi: 10.1007/s11705-018-1722-y

摘要: With the development of carbon catalysts, graphene-based metal-free catalysts have drawn increasing attention in both scientific research and in industrial chemical production processes. In recent years, the catalytic activities of metal-free catalysts have significantly improved and they have become promising alternatives to traditional metal-based catalysts. The use of metal-free catalysts greatly improves the sustainability of chemical processes. In view of this, the recent progress in the preparation of graphene-based metal-free catalysts along with their applications in catalytic oxidation, reduction and coupling reactions are summarized in this review. The future trends and challenges for the design of graphene-based materials for industrial organic catalytic reactions with good stabilities and high catalytic performance are also discussed.

关键词: graphene-based materials     metal-free catalyst     industrial chemical productions     catalytic reaction    

标题 作者 时间 类型 操作

Zinc modification of Ni-Ti as efficient NiZnTi catalysts with both geometric and electronic improvements for hydrogenation of nitroaromatics

期刊论文

Catalytic activity of noble metal nanoparticles toward hydrodechlorination: influence of catalyst electronic

Man ZHANG,Feng HE,Dongye ZHAO

期刊论文

Hydro-pyrolysis of lignocellulosic biomass over alumina supported Platinum, Mo

Songbo He, Jeffrey Boom, Rolf van der Gaast, K. Seshan

期刊论文

Highly uniform Ni particles with phosphorus and adjacent defects catalyze 1,5-dinitronaphthalene hydrogenation with excellent catalytic performance

Wei Xiong, Susu Zhou, Zeyong Zhao, Fang Hao, Zhihui Cai, Pingle Liu, Hailiang Zhang, Hean Luo

期刊论文

Exploration of the oxygen transport behavior in non-precious metal catalyst-based cathode catalyst layer

Shiqu CHEN, Silei XIANG, Zehao TAN, Huiyuan LI, Xiaohui YAN, Jiewei YIN, Shuiyun SHEN, Junliang ZHANG

期刊论文

Hollow carbon spheres and their noble metal-free hybrids in catalysis

期刊论文

Effect of noble metal nanoparticle size on C–N bond cleavage performance in hydrodenitrogenation: a study

期刊论文

Shape/size controlling syntheses, properties and applications of two-dimensional noble metal nanocrystals

Baozhen An,Mingjie Li,Jialin Wang,Chaoxu Li

期刊论文

Copper nanoparticles/polyaniline-derived mesoporous carbon electrocatalysts for hydrazine oxidation

Tao Zhang, Tewodros Asefa

期刊论文

Diffusion process in enzyme–metal hybrid catalysts

期刊论文

Noble-metal-free cobalt hydroxide nanosheets for efficient electrocatalytic oxidation

Jie Lan, Daizong Qi, Jie Song, Peng Liu, Yi Liu, Yun-Xiang Pan

期刊论文

Micro-sized hydrothermal carbon supporting metal oxide nanoparticles as efficient catalyst for mono-dehydration

Cheng PAN, Chao FAN, Wanqin WANG, Teng LONG, Benhua HUANG, Donghua ZHANG, Peigen SU, Aqun ZHENG, Yang SUN

期刊论文

Fischer-Tropsch synthesis by reduced graphene oxide nanosheets supported cobalt catalysts: Role of support and metalnanoparticle size on catalyst activity and products selectivity

Hasan Oliaei Torshizi, Ali Nakhaei Pour, Ali Mohammadi, Yahya Zamani, Seyed Mehdi Kamali Shahri

期刊论文

非并网风电应用中金属材料清洗与防护技术

吴 昊,邹宜哲,白 珂

期刊论文

Recent advances on metal-free graphene-based catalysts for the production of industrial chemicals

Zhiyong Wang, Yuan Pu, Dan Wang, Jie-Xin Wang, Jian-Feng Chen

期刊论文