JOURNAL OF CATALYSIS
·
2024
·
IF 6.5
Gongcheng Sun,Subing Fan,Junmin Lv,Tiansheng Zhao
A hollow zeolite encapsulated Rh catalyst Rh@H-S-1 with an “eggshell” structure was prepared using the method of organic alkali treatment and recrystallization. Compared with catalysts with directly encapsulated Rh@S-1 and surface impregnated Rh/S-1, this catalyst exhibited both superior activity and a higher TOF value in hydroformylation of 1-hexene due to the high dispersion of Rh and high diffusion. The Rh element did not need to be reduced in the preparation, and it was in situ reduced by the syngas. The content of lower valence Rh δ+ gradually increased with the reaction procedure and played as an active center. The low oxidized state Rh + or Rh δ+ in the form of Rh(CO) 2 are proposed as active sites in hydroformylation, which were generated under the synergistic effect between CO and H 2 . Importantly, the hollow encapsulated catalyst effectively decreased Rh leaching to 0.1 ppm and showed better stability compared with the impregnated Rh/S-1 catalyst.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Kaiting Chen,Xinyu Han,Qian Wang,Kaijie Liu,Xiangguang Yang,Yibo Zhang
The selective catalytic reduction of NO by CO (CO-SCR) presents an economical and promising approach to mitigate emissions of NO x and CO from motor vehicles. A bimetallic Rh-Mn supported catalyst Rh-Mn/CoAlO was synthesized through the reduction of citric acid and ethylene glycol, and subsequently employed in the CO-SCR reaction. Tests assessing its catalytic performance revealed that the Rh-Mn/CoAlO catalyst displayed superior CO-SCR activity, maintaining high efficiency (≥90 % at 230 °C) and stability while simultaneously reducing the usage of noble metals. Various characterization techniques, including H 2 -TPR, NO-TPD, CO-pulse, and XPS, indicated that the Rh-Mn/CoAlO catalyst possessed enhanced dispersion of noble metals. This increased dispersion ensured optimal contact between Rh and Mn, as well as the support, fostering a synergistic interaction that facilitated electron transfer. Consequently, the catalyst’s adsorption and activation capabilities for NO were significantly improved. In situ DRIFTs studies further elucidated that the catalyst primarily followed the E-R mechanism, wherein NO is adsorbed onto the catalyst surface, and subsequently, the N and O atoms generated from pyrolysis react with CO in the gas phase. The findings of this study are anticipated to offer an effective strategy for designing catalysts with exceptional low-temperature activity and high dispersibility for the reduction of NO using CO.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Gongcheng Sun,Wan Chen,Yaoying Li,Subing Fan,Junmin Lv,Tiansheng Zhao
The hydroformylation reaction is very important in industry. However, the leaching of the noble metal Rhodium (Rh) and the separation of homogeneous catalyst have always been difficult problems to solve. And even heterogeneous Rh-base catalyst was developed to solve the separation problem, the serious Rh losing is still hard to avoid. In this work, heterogeneous encapsulated Rh@NaX was prepared by using one-step synthesis method and used as catalyst without reduction in 1-hexene hydroformylation reaction. Rh@NaX catalyst exhibited outstanding catalytic performance. When directly complexed with ligand triphenylphosphine (PPh 3 ), it achieved high heptanal yield of 97.53 %, high n/i ratio of 2.59 and high TOF of 6588 h −1 . Interestingly, encapsulated catalyst exhibited higher recycling stability and much lower Rh leaching compared to impregnated catalyst. In addition, in situ XPS and DRIFT analyses were conducted to elucidate the reduction process of Rh and the reaction pathway.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2025
·
IF 21.1
Wuyi Feng,Jiantao Fu,Xinye Zheng,Wei Zhu,Zhongbin Zhuang,Di Zhao,Jiatao Zhang
Optimizing the intrinsic hydrogen binding energy at atomic-level interfaces is beneficial and challenging for hydrogen electrocatalysis to improve the mass activity of platinum-group metal. Here, we develop a bifunctional hydrogen electrocatalyst featuring atomically dispersed Rh-N 4 sites alongside ultrasmall Rh nanoparticles (Rh SA+NP /NC). For the hydroxide oxidation reaction, the mass activity (9.14 A mg Rh −1 ) of Rh SA+NP /NC is 101 times that of commercial Pt/C. For the hydrogen evolution reaction, the overpotential is merely 14 mV at an extremely low Rh loading (1.91 μg cm −2 ). The anion-exchange membrane fuel cell and anion-exchange membrane water electrolyzer equipped with Rh SA+NP /NC achieve a high peak power density (25.7 W mg Rh −1 ) and a low cell voltage (1.77 V at 1 A cm −2 ), respectively. Experimental and computational results indicate that the atomic-level interface formed by Rh single atoms and nanoparticles optimizes the adsorption behavior of active species and accelerates the hydrogen conversion kinetics. This study designs cost-effective hydrogen electrocatalysts through atomic-level interface engineering, providing a feasible strategy for accelerating the realization of a sustainable hydrogen circular economy.
研究领域:
电催化
·
材料科学
·
能量转换
·
纳米材料
·
氢能
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2017
·
IF 2.446
Xiao-yu Sun,Chang Liu,Zheng Chen,Yong-qing Ma
In order to reveal the effects of dopant average valence on the photocatalytic performance, Ta and Rh co-doped Ti 0.96 Ta 0.04−x Rh x O 2 (x = 0, 0.008, 0.016, 0.02, 0.024, 0.032, and 0.04) samples were crystallized at 450 °C and 800 °C, respectively; then the 800 °C crystallized x = 0.02 sample was subsequently reduced in the H 2 /N 2 mixture gases at 600, 700, 800, and 900 °C. Under different processing conditions, Ta remains the valence of +5, while the valence of Rh varies. Rh exhibits Rh 3+ and Rh 4+ in the 450 °C crystallized samples and is completely oxidized to Rh 4+ in the 800 °C crystallized samples. In the reduced samples, Rh exists in the forms of Rh, Rh 3+ and Rh 4+ . The optimal photocatalyst is obtained as the ratio of Rh 3+ /Rh 4+ is 2.11 or the average valence of doped Ta and Rh is closest to the +4 valence of substituted Ti.
研究领域:
材料科学
·
化学
·
催化
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 55
·期 27
·13363-13371
·
IF 3.553
Cao Yutao,Yuan Yue,Shang Yafen,Zverev Vladimir I.,Gimaev Radel R.,Barua R.,Hadimani R. L.,Mei Lan,Guo Gang,Fu Hao
Micro-sized particles of Fe x Rh 100− x ( x = 50, 48, 45, 40, and 35) binary alloys were synthesized by a solid-phase reduction method and their structural properties, magnetic properties and cytotoxicity have been characterized. From X-ray diffraction results, the Fe 50 Rh 50 alloy is in a single chemically ordered α ′ phase while the face-centered cubic disordered γ phase arises and increases with Rh content when x is smaller than 50. The magnetization behavior of the alloys demonstrates that the α ′ phase consists of ferromagnetic and antiferromagnetic components due to the nonuniformity of elements in the particulate alloys. The maximal magnetic entropy change and the relative refrigeration capacity of the Fe 50 Rh 50 particles reach 9.7 J/kg K and 230 J/kg, respectively, with a 0–3 T magnetic field change. Despite its moderate magnetic entropy among the first-order transition materials, Fe 50 Rh 50 microparticles are promising for biomedical applications due to its large relative cooling power and low cytotoxicity.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2024
·
IF 15.7
Shuyi Li,Changle Mu,Nianqiu He,Jie Xu,Yanping Zheng,Mingshu Chen
ABSTRACT The surface structures of heterogeneous catalysts significantly impact catalytic performance, especially for structure-sensitive reactions. In this study, we employed surface techniques such as low-energy ion scattering spectroscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy with CO as a probe (CO-FTIR) to investigate the surface dynamics of Rh/Al 2 O 3 catalysts for propane dehydrogenation (PDH). We observed a notable induction process for PDH on Rh/Al 2 O 3 catalysts, marked by significant variations in propane conversion, methane, and propylene selectivities. These changes were attributed to substantial coke formation. Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy) and CO-FTIR revealed the coexistence of Rh nanoparticles , clusters, and single atoms on the surface. Through various dynamic quasi in-situ characterizations, we found that coke preferentially covered Rh clusters, thereby inhibiting C–C bond breaking and methane formation. Meanwhile, Rh single atoms were less affected by coke coverage and remained exposed as active and selective sites for PDH, favoring propylene production. This work underscores the sensitivity of PDH to the sizes of Rh species, with isolated Rh single atoms promoting propylene formation.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
Journal of the American Chemical Society
·
2025
·
IF 15.6
Jun Mao,Huan Liu,Yanan Li,Meng Gao,Yunlong Zhang,Yao Song,Mo Zhang,Guilan Xu,Wu Zhou,Liang Yu,Xiaoju Cui,Dehui Deng
The oriented conversion of CH4 to CH3COOH at low temperature, even room temperature, is both scientifically significant and industrially applicable for CH4 utilization, yet it is extremely challenging due to the difficulties associated with efficient CH4 activation and controllable C–C coupling. In this study, we for the first time achieve the room-temperature conversion of CH4 to CH3COOH using molecular O2 and CO over MoS2-confined Rh–Fe sites, which delivers an unprecedented CH3COOH selectivity of 90.3% and a productivity of 26.2 μmol gcat.–1 h–1 at 25 °C. Furthermore, the productivity of CH3COOH can be enhanced to 105.6 μmol gcat.–1 h–1 at 80 °C, while maintaining a high selectivity of 95.6%. Comprehensive experimental and theoretical investigation reveal the critical role of Rh–Fe synergy in the selective formation of CH3COOH. The confined Fe sites in MoS2 enable the activation of O2 to generate highly reactive Fe═O center for CH4 dissociation to CH3 species at room temperature, which then readily couple with adsorbed CO on adjacent Rh sites to form the key CH3CO intermediate for CH3COOH production. The unique structure of Rh–Fe sites offers synergistic catalytic properties that effectively balance C–H activation and C–C coupling, successfully addressing the trade-off between activity and selectivity in the carbonylation of CH4 to CH3COOH under mild conditions.
研究领域:
化学
·
催化反应
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Physical Chemistry C
·
2021
·
IF 4.126
Zhaolong Xie,Menghuan Chen,Yangshen Chen,Anxiang Guan,Qing Han,Gengfeng Zheng
The direct conversion of methane to value-added chemicals at ambient conditions is a long-awaited perspective, and the electrocatalytic methane oxidation reaction (CH4OR) offers the potential of utilizing abundant natural gas and renewable energy sources. However, due to the competition of water oxidation and the overoxidation of methane, CH4OR has remained as a significant challenge. In this work, we developed Rh/ZnO nanosheets as an effective catalyst for electrochemical conversion of methane into ethanol. The highly dispersed rhodium nanoparticles provided surface sites for methane adsorption, and ZnO allowed presentation of abundant active oxygen species for methane activation. With a 0.6% Rh doping ratio, the Rh/ZnO nanosheets demonstrated an excellent ethanol production rate of 789 μmol·gcat–1·h–1 at 2.2 V versus reversible hydrogen electrode, corresponding to a Faradaic efficiency of 22.5% and an ethanol production selectivity of 85%, suggesting a promising means for methane utilization at ambient conditions.
研究领域:
化学工程
·
能源科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 33
·16035-16039
·
IF 3.925
Jing Zhang,Chunlei Li,Xingzhi Jin,Yi Zheng
Shape anisotropic semiconductors are advanced catalysts for resolving energy crises. However, modification studies are still needed to overcome their intrinsic disadvantages, such as the lack of active sites. With this aim, an excellent hydrogen evolution photocatalyst Rh@Cr2O3-loaded PbMoO4 twenty-six facet polyhedron (PM/Rh@Cr2O3) has been synthesized by a liquid method. Based on XPS, electrochemical investigation and hydrogen evolution reaction (HER) test, it is demonstrated that Rh acts as an electron collector and active site; moreover, Cr2O3 can assist Rh in the dissociation of water. In addition, Cr2O3 can also inhibit the reverse reaction of water splitting as well as the mass transfer of water. In conclusion, the H2 yield rate increased from 0 μmol g−1 h−1 of PbMoO4 (PM) to 704 μmol g−1 h−1 of PM/Rh@Cr2O3, and PM/Rh@Cr2O3 exhibited excellent photo-stability.
研究领域:
材料科学
·
能源化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 32
·期 10
·14102-14112
·
IF 2.478
Gao Ying,Zhang Jinniu,Leng Deying,Li Gang,Zhang Yuanyi,Wang Wei,Liang Qingfei,Chen Xiaorui,Lu Hongbing,Gao Jianzhi
Construction of high-performance gas sensors based on p-type metal oxides is still a big challenge. In this work, with the objective of improving the sensing properties of p-type NiO, a series of porous Rh–NiO heterojunction nanofibers with various molar ratios (Rh/Ni = 3%, 5% and 7%) are fabricated by a facile electrospinning technique. The effects of Rh content on surface area, oxygen species absorbing capability, as well as acetone sensing properties of NiO nanofibers are systematically investigated. Sensing results demonstrate that the Rh–NiO sensor with an optimal Rh amount of 5 mol% exhibits the highest p-type response of 70.10 to 200 ppm acetone at 225 °C, which is 37.9 times higher than that of pure NiO nanofiber sensor. Moreover, the 5 mol% Rh–NiO nanofibers also possess excellent acetone selectivity. The improved sensing response of Rh–NiO nanofibers is mainly attributed to the formation of ohmic contacts between Rh nanoparticles and NiO nanoparticles, facilitating the reduction of sensor resistance in air and the increase of chemisorbed oxygen capability. Chemical sensitization effect of Rh nanoparticles and increased BET surface area also contribute to the improved acetone response of Rh–NiO nanofibers.
研究领域:
材料科学
·
传感器技术
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED SYNTHESIS & CATALYSIS
·
2021
·Vol. 363
·期 6
·1672-1684
·
IF 5.837
Zhipeng Liu,Xinwei Hu,Can Yang,Haisheng Xie,Huanfeng Jiang,Wei Zeng
Graphical A Rh(III)-catalyzed C sp 2 −C sp 3 bond cleavage/carbonylethylation of α-indolyl alcohols with allylic alcohols has been reported. This transformation involved a cascade C−C bond cleavage/C−C bond formation, and provides a novel approach to assemble 2-carbonylethylindole skeletons.
研究领域:
有机化学
·
催化反应
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）