Scientific Reports
·
2017
·Vol. 7
·期 1
·1-10
·
IF 4.259
Wang Guojing,Jing Shengchang,Tan Yiwei
Shape control of noble metal (NM) nanocrystals (NCs) is of great importance for improving their electrocatalytic performance. In this report, branched Pd@Rh core@shell NCs that have right square prism-like arms with preferential exposure of Rh {100} facets (denoted as b-Pd@Rh-NCs thereafter) are synthesized and utilized as an electrocatalyst for the hydrazine electrooxidation (HEO) in acidic and alkaline electrolytes. The b-Pd@Rh-NCs are obtained by the heteroepitaxial growth of Rh on the pre-formed branched Pd NCs (denoted as b-Pd-NCs thereafter) core in the presence of poly(vinyl pyrrolidone) (PVP) and bromide ions. A comparative analysis of the voltammetric data for the HEO shows a higher activity on the b-Pd@Rh-NCs exposed with Rh {100} faces than on Rh black, the b-Pd-NCs, and Pd black in acid and alkaline solutions, indicating a structure sensitivity of the reaction. Analysis of the products from the b-Pd@Rh-NCs catalysed HEO reveals a very high hydrazine fuel efficiency, as determined by on-line differential electrochemical mass spectrometry (DEMS).
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Yu-Chuan Jiang,Hui-Ying Sun,Ya-Nan Li,Jia-Wei He,Qi Xue,Xinlong Tian,Fu-min Li,Shi-Bin Yin,Dong-Sheng Li,Yu Chen
Methanol electrolysis is a promising strategy to achieve energy-saving and efficient electrochemical hydrogen (H2) production. In this system, the advanced electrocatalysts with high catalytic performance for both the methanol oxidation reaction (MOR) and hydrogen evolution reaction (HER) are highly desirable. Inspired by the complementary catalytic properties of rhodium (Rh) and palladium (Pd) for MOR and HER, herein, several Pd core–RhPd alloy shell nanodendrites (Pd@RhPd NDs) are synthesized through the galvanic replacement reaction between Pd nanodendrites (Pd NDs) and rhodium trichloride. For MOR, Pd@RhPd NDs exhibit Rh content-determined catalytic activity, in which Pd@Rh0.07Pd NDs have an optimal combination of oxidation potential and oxidation current due to the synergistic catalytic process of Pd/Rh double active sites. For HER, the introduction of Rh greatly improves the catalytic activity of Pd@RhPd NDs compared to that of Pd NDs, suggesting that Rh is the main activity site for HER. Unlike MOR, however, the HER activity of Pd@RhPd NDs is not sensitive to the Rh content. Using Pd@Rh0.07Pd NDs as robust bifunctional electrocatalysts, the as-constructed two-electrode methanol electrolysis cell shows a much lower voltage (0.813 V) than that of water electrolysis (1.672 V) to achieve electrochemical H2 production at 10 mA cm–2, demonstrating the application prospect of methanol electrolysis for H2 production.
研究领域:
材料科学
·
电化学
·
能源科学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Hanqin Weng,Yi Wang,Fuhai Li,Yusa Muroya,Shinichi Yamashita,Sheng Cheng
Recovery of platinum group metals (PGMs) including palladium (Pd), rhodium (Rh), and ruthenium (Ru) from high-level radioactive liquid waste (HLLW) possesses enormous environmental and economic benefits. A non-contact photoreduction method was herein developed to selectively recover each PGM from HLLW. Soluble Pd(II), Rh(III), and Ru(III) ions were reduced to insoluble zero-valent metals and separated from simulated HLLW containing neodymium (Nd) as a representative for lanthanides , another main component in HLLW. Detailed investigation on the photoreduction of different PGMs revealed that Pd(II) could be reduced under 254- or 300-nm UV exposure using either ethanol or isopropanol as reductants. Only 300-nm UV light enabled the reduction of Rh(III) in the presence of ethanol or isopropanol. Ru(III) was the most difficult to reduce, which was only realized by 300-nm UV illumination in isopropanol solution. The effects of pH was also studied, suggesting that lower pH favored the separation of Rh(III) but hindered the reduction of Pd(II) and Ru(III). A delicate three-step process was accordingly designed to achieve the selective recovery of each PGM from simulated HLLW. Pd(II) was reduced by 254-nm UV light with the help of ethanol in the first step. Then Rh(III) was reduced by 300-UV light in the second step after the pH was adjusted to 0.5 to suppress the Ru(III) reduction. In the third step, Ru(III) was reduced by 300-nm UV light after isopropanol was added and the pH was adjusted to 3.2. The separation ratios of Pd, Rh, and Ru exceeded 99.8%, 99.9%, and 90.0%, respectively. Meanwhile, all Nd(III) still remained in the simulated HLLW. The separation coefficients between Pd/Rh and Rh/Ru exceeded 56,000 and 75,000, respectively. This work may provide an alternative method to recover PGMs from HLLW, which minimize the secondary radioactive wastes compared with other approaches.
研究领域:
环境科学
·
核化学与放射化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nuclear Science and Techniques
·
2020
·Vol. 31
·期 4
·1-13
·
IF 1.556
Zhang Shi-Chang,Ning Shun-Yan,Zhou Jie,Wang Si-Yi,Zhang Wei,Wang Xin-Peng,Wei Yue-Zhou
A porous silica-polymer-based adsorbent, iso Bu-BTP/SiO 2 -P, was prepared by a vacuum impregnation method and used for the recovery of ruthenium, rhodium, and palladium from nitric acid solution. The experimental results revealed that iso Bu-BTP/SiO 2 -P exhibited unique adsorption properties such as high saturation adsorption capacity (Ru: 0.35 mmol g −1 , Rh: 0.32 mmol g −1 , Pd: 1.05 mmol g −1 ) and excellent selectivity over other metal ions, such as lanthanides (SF PGM/ M > 40) in 1 M HNO 3 solution. The adsorption process conformed to the pseudo-second-order model and Langmuir model. From the UV, FTIR, and XPS analyses, it can be concluded that the strong affinity between functional groups (C–N=C) and metal ions as well as NO 3 − played a role in coordination during the adsorption process. Furthermore, the desorption behavior was studied, and it was found that the adsorbed Pd, Rh, and Ru could be eluted with a 0.01 M nitric acid–0.1 M thiocarbamide solution, 5 M hydrochloric acid, and sodium hypochlorite (CP) solution, respectively. Finally, based on those findings, a simple process for the separation and recovery of Pd, Rh, and Ru from high-level liquid waste using iso Bu-BTP/SiO 2 -P was designed and proposed.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
ACS Catalysis
·
2022
·
IF 13.7
Danfeng Wu,Sixu Liu,Mingqi Zhong,Jiafei Zhao,Congcong Du,Yanling Yang,Yifei Sun,Jingdong Lin,Shaolong Wan,Shuai Wang,Jianyu Huang,Yali Yao,Zhe Li,Haifeng Xiong
Metal single-atom catalysts (SACs) have attracted extensive interest because of their maximum atom efficiency and potentially good performances. However, the understanding of the catalytic behavior and the stability of SACs in high-temperature catalytic reactions remains a major challenge, especially under reducing conditions. In this work, we investigated the nature and stability of Rh/CeO2 SACs with different Rh loadings (0.2–4 wt % Rh) during syngas conversion (260 °C, 2 MPa). Using CO-DRIFTS, we found that atomically dispersed Rh was dispersed on Rh/CeO2 catalysts with an Rh loading up to 3 wt %. The Rh/CeO2 catalysts were stable in H2 up to 350 °C, while Rh nanoclusters were formed in CO at 200 °C. During syngas conversion at 260 °C, the Rh single atoms (Rhiso) on a 0.5 wt % Rh/CeO2 SAC slowly agglomerated to form Rh nanoclusters (RhNC) and a Rhiso/RhNC ratio of ∼1:2.5 was obtained after ∼10 h time-on-stream run. Furthermore, the Rhiso/RhNC ratio did not change with further reaction, indicating that the reaction reached steady state after a 10 h run. After the catalysts reached steady state (∼10 h), the Rhiso/RhNC ratio on the spent Rh/CeO2 catalysts decreased with the increase in Rh loadings, while the reactivity increased first and then decreased. We observed an optimal value of Rhiso/RhNC ≈ 1:3 on the 1 wt % Rh/CeO2 catalyst, showing the maximum reaction rates of CO (rCO) and ethanol selectivity (SEtOH) of 85.8 μmol/s/gRh and 26.2%, respectively. This indicated that the combination of Rh single atoms and Rh nanoclusters is beneficial to the ethanol selectivity and reaction rate, which was confirmed by DFT simulations. Moreover, the ratios of Rhiso/RhNC on the spent catalysts under the steady state have good relationships with the CO conversion rate and product selectivity in the reaction.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Xia Wei,Bing Fang,Tianyao Wang,Hongbin Dai,Song Li
Understanding the metal-support interaction between Rh-B and CeO 2 is essential for enhancing the efficiency of hydrogen generation from hydrous hydrazine. In this study, a series of Rh-B/CeO 2 catalysts were synthesized via a facile wet-chemical reduction method. The Rh-B/(CeO 2 ) 0.7 catalyst exhibits a remarkable 12-fold increase in turnover frequency (TOF) compared to pristine Rh-B catalyst. The strong electronic coupling between Rh-B and CeO 2 was identified as the primary factor driving this significant performance enhancement. This interaction facilitates the formation of oxygen vacancies, promoting hydrazine adsorption and subsequent cleavage of the N-H bond in N 2 H 4 * to form N 2 H 3 *. Our findings emphasize the pivotal role of support engineering in catalyst design for optimizing catalytic performance.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2021
·Vol. 151
·期 9
·2638-2646
·
IF 3.186
Li Xiao,Qin Tingting,Li Liusha,Wu Bo,Lin Tiejun,Zhong Liangshu
Abstract A green route for one−pot synthesis of acetals by tandem hydroformylation−acetalization of olefins using supported Rh−based catalysts was developed. Experimental results demonstrated that suitable Rh loading (1 wt%) with appropriate reaction temperature (120 °C) and reaction time (8 h) were favorable for the formation of acetals, and a high acetals selectivity of 94.6% was achieved. More importantly, the selectivity to valuable linear products was enhanced in this tandem catalysis. Based on the catalytic mechanism study, highly dispersed RhO x nanoparticles and abundant acid sites on the supports were responsible for the hydroformylation and acetalization, respectively. Graphical abstract One-pot synthesis of acetals directly from olefins with high selectivity was achieved over heterogeneous bifunctional catalysts via tandem hydroformylation-acetalization.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION SCIENCE AND TECHNOLOGY
·
2018
·
IF 1.2
Yan Yan,Qi Wang,Zeyang Xiang,Yanzhao Yang
A reasonable project was presented for the extraction and separation of Pt(IV), Pd(II), Ru(III), and Rh(III) from the mixed imidazolium-based ionic liquids (ILs) [C6mim]Cl, [C6mim][NTf2], and [C6mim][DDTC]. Pt(IV) was first separated from other three platinum group metals with a mixture of [C6mim]Cl and [C6mim][NTf2]. Then, separation of Pd(II) and Ru(III) from Rh(III) was realized by changing the concentration of [C6mim][DDTC]. Back-extraction of Pt(IV), Pd(II), and Ru(III) from loaded hydrophobic phase and the recovery of Rh(III) in aqueous phase were also investigated. Mechanisms between Pd(II)/Ru(III) and [C6mim][DDTC] were further explored using ultraviolet spectrophotometry (UV-Vis), infrared spectrophotometry (FTIR), the method of continuous variations, ab initio quantum chemical studies, and X-ray crystallographic analysis. The results afford more directions for extracting and separating metals by introducing devisable functionalized group into ILs.
研究领域:
化学工程
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2018
·
IF 6.759
Zenan Hu,Junjie Zhou,Yongjian Ai,Lei Liu,Li Qi,Ruihang Jiang,Hongjie Bao,Jingting Wang,Jianshe Hu,Hong-bin Sun,Qionglin Liang
A magnetically separable 2D Rh/Fe 3 O 4 /g-C 3 N 4 -N catalyst has been synthesized for the catalytic transfer hydrogenation of nitroarenes to afford corresponding anilines. The highly dispersed Rh nanoparticles are the dominant active species. The reaction is second order for rhodium according to the kinetic study, and this means the activity of different Rh-containing catalyst can be precisely predicted and the active site contains two adjoining rhodium atoms. The strong interaction between Rh and Fe 3 O 4 contributes to the catalytic performance, therefore the obtained Rh/Fe 3 O 4 /g-C 3 N 4 -N catalyst exhibits excellent catalytic activity and chemoselectivity for the reduction of various nitroaromatics, and the turnover frequencies (TOF) can reach as high as 12,666 h −1 for 4-nitrophenol. Moreover, this catalytic system is environmentally friendly because of its green solvent water and harmless byproducts (H 2 O and N 2 ), and the catalyst shows outstanding stability and recyclability with at least 12 cycles.
研究领域:
化学
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Huanhuan Zhang,Qunying Sun,Linyan Bian,Qiuming Peng,Shumin Han,Baozhong Liu,Yanping Fan
Developing noble-based catalysts with high activity is the key to realizing high-efficiency hydrogen generation. Herein, PdRh alloys with different ratios supported on active Ti 3 C 2 is designed by microwave-assisted reduction to enhance the dissociation of NH 3 BH 3 and H 2 O. Specially, Pd 1 Rh 4 /Ti 3 C 2 conveys an optimal turnover frequency ( TOF ) of 338 min −1 and activation energy ( E a ) of 33.8 kJ mol −1 at room temperature. The TOF of Pd 1 Rh 4 /Ti 3 C 2 is 7.3 times than that of Pd/Ti 3 C 2 and 4.8 times of Rh/Ti 3 C 2 because of the construction of dual-active sites of PdRh alloy and active Ti 3 C 2 . The introduction of a small number of Pd changes the chemical environment of catalysts and presents significant excitation effect on catalytic activity. Experimental investigation reveals PdRh alloy and active Ti 3 C 2 are beneficial for the adsorption and dissociation of NH 3 BH 3 and H 2 O (active Ti 3 C 2 activates H 2 O, PdRh activates NH 3 BH 3 ). This research provides experimental foundation for the design of noble-based catalysts with high catalytic activity.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Xiaofeng Ke,Feng Zhou,Yihuang Chen,Mei Zhao,Yun Yang,Huile Jin,Youqing Dong,Chao Zou,Xi'an Chen,Lijie Zhang,Shun Wang
Sluggish kinetics of hydrogen oxidation reaction (HOR) in alkaline solution has restricted the rapid development of hydrogen economy. Constructing catalyst with metal-oxide heterostructures can enhance HOR performance; however, little studies concentrate on charge transfer between them, and the corresponding effects on reactions remain unclear. Herein, we report charge-transfer-adjustable CeO 2 /Rh interfaces uniformly dispersed on multiwalled carbon nanotube (CNT), which exhibit excellent alkaline HOR performance. Results confirm that the charge transfer from Rh to CeO 2 could be conveniently tuned via thermal treatment. Consequently, the adsorption free energies of H* in Rh sites and OH* adsorption strength in CeO 2 could be adjusted, as corroborated by density functional theory study. The optimized CeO 2 /Rh interfaces exhibit an exchange current density and a mass-specific kinetic current of 0.53 mA cm PGM −2 and 830 A g PGM −1 at an overpotential of 50 mV, respectively, which surpasses most of the advanced noble-metal-based electrocatalysts. This work provides a new insight of harnessing charge transfer of heterostructure to enhance catalytic activities.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysts
·
2022
·Vol. 12
·期 10
·1146
·
IF 4.501
Jikang Yao,Yuanjie Xu,Hua Yang,Zhuangzhuang Ren,Lizhi Wu,Yu Tang
The partial oxidation of methane (POM) is a promising method for converting methane to syngas. The transition metal supported on boron nitride (BN) has recently been studied as part of a catalog of emerging catalysts. However, the chemical state of the metal supported on BN during methane reforming is still in debate. In this work, we report a rhodium catalyst on boron nitride (Rh/BN) for the POM, with exceptional activity and long-term stability at 600 °C for 230 h. The Rh/BN catalyst was investigated by X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, transmission electron microscopy, and diffuse reflectance infrared Fourier transformed spectroscopy (DRIFTS). As revealed by in situ DRIFTS, the infrared band (2020 cm−1) of the product molecule, CO, adsorbed on the Rh, as the probe confirms the metallic state of Rh during the POM reaction. In addition, the results of in situ DRIFTS indicate that the reactive gaseous environment would react with the catalyst to form B-OH and B-H, which synergistically boost the POM activity.Keywords:partial oxidation of methane;syngas;boron nitride;rhodium;DRIFTS
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）