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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

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Non-toxic, high selectivity process for the extraction of precious metals from waste printed circuit

《环境科学与工程前沿（英文）》 2023年第17卷第10期 doi: 10.1007/s11783-023-1723-z

摘要：

● Au, Ag and Pd were recovered from WPCBs with high efficiencies.

关键词： Thiosulfate Printed circuit boards Precious metals Leaching Hydrometallurgy

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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 (Ni_xZn_yTi₁) 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 Ni^δ^– obtained by electron transfer from Zn and Ti to Ni effectively adsorbs and dissociates hydrogen. The results reveal that Ni_xZn_yTi₁ (Ni_0.5Zn_0.5Ti₁) 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

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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

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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

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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

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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

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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 NO_x elimination.

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

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A critical review on the recycling of copper and precious metals from waste printed circuit boards using

Zebing Wu, Wenyi Yuan, Jinhui Li, Xiaoyan Wang, Lili Liu, Jingwei Wang

《环境科学与工程前沿（英文）》 2017年第11卷第5期 doi: 10.1007/s11783-017-0995-6

摘要： Currently, increasing amounts of end-of-life (EoL) electronic products are being generated due to their reduced life spans and the unavailability of suitable recycling technologies. In particular, waste printed circuit boards (PCBs) have become of global concern with regard to environmental issues because of their high metal and toxic material contents, which are pollutants. There are many environmental threats owed to the disposal of electronic waste; off-gasses, such as dioxins, furans, polybrominated organic pollutants, and polycyclic aromatic hydrocarbons, can be generated during thermal treatments, which can cause serious health problems if effective off-gas cleaning systems are not developed and improved. Moreover, heavy metals will dissolve, and release into the ground water from the landfill sites. Such waste PCBs contain precious metals which are of monetary value. Therefore, it is beneficial to recover the metal content and protect the environment from pollution. Hydrometallurgy is a successful technique used worldwide for the recovery of precious metals (especially gold and silver) from ores, concentrates, and waste materials. It is generally preferred over other methods because it can offer high recovery rates at a relatively low cost. This article reviews the recent trends and developments with regard to the recycling of precious metals from waste PCBs through hydrometallurgical techniques, such as leaching and recovery.

关键词： Waste PCBs Precious metals Hydrometallurgy Recycling Leaching Recovery

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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

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Recovery of rare and precious metals from urban mines—A review

Mengmeng Wang, Quanyin Tan, Joseph F. Chiang, Jinhui Li

《环境科学与工程前沿（英文）》 2017年第11卷第5期 doi: 10.1007/s11783-017-0963-1

摘要： Urban mining is essential for continued natural resource extraction. The recovery of rare and precious metals (RPMs) from urban mines has attracted increasing attention from both academic and industrial sectors, because of the broad application and high price of RPMs, and their low content in natural ores. This study summarizes the distribution characteristics of various RPMs in urban mines, and the advantages and shortcomings of various technologies for RPM recovery from urban mines, including both conventional (pyrometallurgical, hydrometallurgical, and biometallurgical processing), and emerging (electrochemical, supercritical fluid, mechanochemical, and ionic liquids processing) technologies. Mechanical/physical technologies are commonly employed to separate RPMs from nonmetallic components in a pre-treatment process. A pyrometallurgical process is often used for RPM recovery, although the expensive equipment required has limited its use in small and medium-sized enterprises. Hydrometallurgical processing is effective and easy to operate, with high selectivity of target metals and high recovery efficiency of RPMs, compared to pyrometallurgy. Biometallurgy, though, has shown the most promise for leaching RPMs from urban mines, because of its low cost and environmental friendliness. Newly developed technologies—electrochemical, supercritical fluid, ionic liquid, and mechanochemical—have offered new choices and achieved some success in laboratory experiments, especially as efficient and environmentally friendly methods of recycling RPMs. With continuing advances in science and technology, more technologies will no doubt be developed in this field, and be able to contribute to the sustainability of RPM mining.

关键词： Rare and precious metals (RPMs) Distribution characteristics Recycling technology Emerging technology Supercritical fluid

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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

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Modified iron-molybdate catalysts with various metal oxides by a mechanochemical method: enhanced formaldehyde

Xue Liu, Lingtao Kong, Shengtao Xu, Chaofan Liu, Fengyun Ma

《化学科学与工程前沿（英文）》 2021年第15卷第5期页码 1099-1110 doi: 10.1007/s11705-020-2008-8

摘要： A mechanochemical method was employed to prepare modified iron molybdate catalysts with various metal salts as precursors. The physicochemical properties of the iron molybdate catalysts were characterized, and their performances in catalyzing the reaction from methanol to formaldehyde (HCHO) were evaluated. Iron molybdate catalysts doped with Co(NO ) ·6H O and Al(NO ) ·9H O resulted in high HCHO yields. Compared with a commercial catalyst, the HCHO yields in the reaction with the modified catalyst at an optimal Co/Mo molar ratio reached 97.37%. According to chemical state analysis, the formation of CoO and the efficient decrease in the MoO sublimation rate could be important factors enhancing the HCHO yield in reactions catalyzed with iron molybdate doped with different Co/Mo mole ratios.

关键词： iron molybdate catalyst metal oxides methanol to formaldehyde Co/Mo ratio formaldehyde yield

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地下金属矿山无间柱连续采矿可靠性分析与设计

古德生,邓建,李夕兵

《中国工程科学》 2001年第3卷第1期页码 51-57

摘要：

针对传统的两步骤采矿存在的一系列弊端，提出地下金属矿无间柱连续采矿理论与新的工艺技术。根据试验矿山的采矿技术条件，详细叙述了无间柱连续采矿的技术思路、技术要点和工业试验回采方案。方案中临时矿壁和1分区充填体的稳定性，对管理采场地压、有效控制大量出矿时的矿石损失贫化起着决定性作用。本文建立了临时矿壁的抗倾覆条件极限状态方程和强度条件极限状态方程，进行了临时矿壁抗倾覆稳定可靠性和强度稳定可靠性的分析与设计；建立了1分区充填体的三维极限状态方程，计算出1分区充填体的可靠指标和安全系数。

关键词：地下金矿矿山无间柱连续采矿可靠性临时矿壁充填体

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从原子结构探讨贵金属在提取冶金过程中的行为

陈景

《中国工程科学》 1999年第1卷第2期页码 34-40

摘要：

从原子结构特征分析了第Ⅷ族和IB族中Fe、Co、Ni、Cu 3d贱金属元素与其余8个贵金属元素化学性质的差异，以及Ru、Rh、Pd、Ag 4d贵金属与Os、Ir、Pt、Au 5d贵金属化学性质的差异。指出横向比较时，它们的化学稳定性都是从左到右增大；纵向比较时，化学稳定性是3d≤4d＜5d。以从硫化铜镍矿中提取富集贵金属为例，讨论了焙烧-还原熔炼-氧化吹炼等火法过程及电解富集、阳极泥硫酸化处理、湿法氯化、加压氧化、选择性还原等湿法过程中贵金属的行为。

关键词：原子结构贵金属提取冶金

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标题作者时间类型操作

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

Non-toxic, high selectivity process for the extraction of precious metals from waste printed circuit

期刊论文

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

Diffusion process in enzyme–metal hybrid catalysts

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

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

期刊论文

A critical review on the recycling of copper and precious metals from waste printed circuit boards using

Zebing Wu, Wenyi Yuan, Jinhui Li, Xiaoyan Wang, Lili Liu, Jingwei Wang

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

Recovery of rare and precious metals from urban mines—A review

Mengmeng Wang, Quanyin Tan, Joseph F. Chiang, Jinhui Li