ChemNanoMat
·
2021
·Vol. 7
·期 11
·1213-1220
·
IF 3.154
Yang Liu,Yong Zhao,Yulong Zhao,Peng Jiang
Graphical We report an efficient and robust Cu-decorated Rh/TiO 2 catalyst that improves the styrene selectivity in selective hydrogenation of phenylacetylene. The appropriate Cu coverage is found to modulate the electronic states of surface Rh atoms and changes the Rh exposed active sites, thus mitigating the overhydrogenation and enhancing the selectivity. Phenylacetylene as an impurity in styrene is poisonous to catalysts for styrene polymerization in the production of polystyrene plastics. The selective hydrogenation of phenylacetylene to styrene is an industrially promising route to overcome this challenge yet lacks cost-effective catalysts to prevent the overhydrogenation of styrene to ethylbenzene. In this work, we report an efficient and robust copper-decorated Rh/TiO 2 catalyst for the selective hydrogenation of phenylacetylene to styrene. By optimizing the copper coverage on TiO 2 supported Rh nanoparticles, we achieved a selectivity of 83% towards styrene formation at a phenylacetylene conversion of 93%. The appropriate Cu coverage is found to modulate the electronic states of surface Rh atoms and changes the Rh exposed active sites, weakening the binding strength of alkene and hydrogen intermediates on Rh and thus mitigating the overhydrogenation and enhancing the selectivity for styrene generation. This work offers insights on the rational design of efficient Rh-based bimetallic catalysts for selective hydrogenation of phenylacetylene to styrene.
研究领域:
化学工程
·
催化材料
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Yinghua Xu,Tingjie Ge,Hongxing Ma,Xufen Ding,Xiaoyong Zhang,Qi Liu
Hydrodefluorination (HDF) is the key step in fluoroaromatic pollutant (FAP) degradation, making the search for efficient HDF catalysts and the determination of the corresponding mechanism a matter of great importance. In this study, we developed an efficient HDF catalyst (a Rh-Pd alloy) and investigated the underlying catalytic reaction mechanism , using 4-fluorophenol (4-FP) as a model FAP. Specifically, the rapid aqueous-phase HDF of 4-FP at pH 3 was achieved on a Rh-Pd alloy-modified Ni foam electrode, which was followed by ring hydrogenation (RH) of the HDF product (phenol) to afford cyclohexanone and cyclohexanol . Inductively coupled plasma optical emission spectrometer (ICP-OES) and thermodynamic analyses showed that, in addition to those supplied by the applied current, the electrons involved in the HDF of 4-FP and the RH of phenol were largely provided by the oxidative dissolution of the Ni foam support. Hydrogenation and cyclic voltammetry experiments indicated that the HDF of 4-FP probably follows an indirect mechanism (featuring adsorbed H atoms as the direct reductant) and that the strength of 4-FP adsorption onto the surface of the catalyst significantly influences its HDF activity.
研究领域:
环境科学
·
电化学
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
Chem Catalysis
·
2024
·
IF 11.5
Fei-Yang Yu,Hao Sun,Hua-Qiao Tan,Yang-Guang Li,Shuit-Tong Lee,Zhen-Hui Kang
The dynamic evolution and structure-performance relationships of single-atom catalysts (SACs) under operating conditions are one of the most concerned hotspots at present. Here, we employed Anderson-type polyoxometalates as a precursor to prepare the SAC Rh-MoS 2 , which shows excellent hydrogen evolution reaction (HER) performance with a mass activity of 4.26 A mg −1 at 100 mV. Such a result is much better than that of 20% Pt/C. Extensive experimental characterization combined with density functional theory (DFT) calculations suggest that the active site undergoes a dynamic evolution from Rh-S to Rh-S/O, while at the same time, the support is transformed from 1T MoS 2 to 1T-2H MoS 2 . It is this dynamic evolution of the catalyst structure that causes a series of changes in the activity, and eventually, a balance between catalytic activity and stability is achieved. This work offers a good research demonstration of the dynamic evolution of SACs under operating conditions and provides a new perspective on the design of SACs.
研究领域:
材料科学
·
理论化学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2017
·
IF 0
Xiang Li,Kaixuan Zhang,Li Qin,Haihong Ma
The kinetic studies of hydroformylation of 1-butene to produce pentanal were investigated by using Rh/PPh 3 complex as homogeneous catalyst, valeraldehyde and its polycondensates as solvent. The experiment was carried out on small hydroformylation continuous reaction installation. The effects of reaction temperature, the concentration of 1-butene, the partial pressure of CO or H 2 and the concentration of rhodium of catalyst on the reaction rate were studied. Based on the reaction mechanism of hydroformylation and the latest research results of hydroformylation kinetics, the kinetic equation suitable for the hydroformylation of 1-butene was established. The parameters of the kinetic equation were regressed and verified with the experimental data. The relationship between the normal/isomeric ratio of pentanal and the partial pressure of CO was further explored.
研究领域:
化学工程
·
催化化学
✓ 已验证
产品关联
DOI
Catalysis Science & Technology
·
2019
·Vol. 9
·期 13
·3454-3468
·
IF 5.726
Huixian Zhong,Jiaming Wang,Kang An,Kegong Fang,Yuan Liu
A catalyst with a novel composition for direct ethanol synthesis from syngas was prepared and investigated in this work, which is Rh nanoparticles (NPs) highly dispersed on La2O3 modified LaFeO3, and the Rh NPs/La2O3–LaFeO3 was loaded on SiO2 with high surface area. The catalyst was prepared by using LaFe1−xRhxO3 in the perovskite phase as the precursor, which was transformed to Rh/La2O3–LaFeO3/SiO2 after reduction. The results showed that, compared to Rh–La2O3/SiO2, the activity and selectivity to ethanol were improved markedly, which was ascribed to the well-matched catalyzing process by the active sites of Rh0, Rh+ (or Rhδ+) and the oxygen vacancies on the surface of LaFeO3; of those, Rh0 dissociatively adsorbed CO and the latter two associatively adsorbed CO. Moreover, the interaction of La2O3 and LaFeO3 donated electrons to rhodium, which effectively adjusted the ratio of CO adsorbed associatively and dissociatively, and thus improved the selectivity to ethanol and lowered the selectivity to methanol. The catalyst also exhibited excellent resistance to the sintering of Rh NPs and to carbon deposition, which was attributed to the confinement of Rh NPs by La2O3 and LaFeO3, the eliminating effect of La2O3 and LaFeO3 and the very high dispersion of Rh NPs.
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
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Jiaxin Zhu,Yihua Chen,Yurong Gu,Hang Ma,Mingyue Hu,Xinlei Gao,Tongzhou Liu
The discharge of widely used per- and poly-fluorinated compounds (PFCs) leads to their environmental prevalence, bioaccumulation and biotoxicity; and attracts researches focusing on their treatment in wastewater. Electrochemical reductive treatment is a promising alternative due to its milder reaction conditions and easy operation. The feasibility of electrochemical reductive decomposition of PFOA using a Rh/Ni cathode was explored. The Rh/Ni cathode was fabricated by coating Rh 3+ on Ni foil through electrodeposition . The Rh coating was primarily elemental and in a Rh(111) crystalline form. PFOA decomposition and defluorination were observed when using the Rh/Ni cathode where DMF was the solvent and the cathode potential was −1.25 V. A hydrodefluorination reaction was considered having occurred. Because possessing d electrons and empty d orbitals, the Rh coating enhanced PFOA adsorption onto the cathode surface and facilitated C F bond activation through Rh···F interactions. Moreover, the Rh(111) crystal helped chemisorb the generated H* and supply it participating in PFOA decomposition. With the continuous interaction of cathode-supplied electrons, C F bond would ultimately dissociate and transform to C H bond by H* substitution. Adding FeCp 2 * as a supporting electrolyte enhanced PFOA decomposition by working as the shuttle facilitating PFOA migration to the cathode surface.
研究领域:
环境科学
·
电化学
·
污染治理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2024
·
IF 18.5
Jie Huang,Jianhang Qiu,Yongqiang Yang,Bing Li,Lianzhou Wang,Hui-Ming Cheng,Gang Liu
Aurivillius compounds-based photocatalysts have attracted extensive interest largely due to their ferroelectric properties and modifiable characteristics arising from the alternate stacking of structural units. However, the interfacial Schottky barrier between such semiconducting compounds as light absorbers and metallic cocatalysts for hydrogen evolution restrains the transfer of photogenerated electrons, resulting in low photocatalytic overall water splitting activity and stability. Here, an anions-induced surface structure transformation strategy is employed to modulate the interface structure between Bi 3 TiNbO 9 as a typical Aurivillius compound and the cocatalyst Rh by in situ growing ultrathin Bi 2 MoO 6 heterolayer on the surface of Bi 3 TiNbO 9 nanosheets. The introduction of Bi 2 MoO 6 heterolayer lowers the energy barrier near the Bi 3 TiNbO 9 surface, which can facilitate the transfer of the photogenerated electrons from bulk to surface and thus the reduction of Rh cocatalyst for highly active hydrogen production. Compared with the Bi 3 TiNbO 9 -Rh photocatalyst, the proportion of low-valence metallic Rh 0 in Bi 2 MoO 6 heterolayer-modified Bi 3 TiNbO 9 -Rh (Bi 3 TiNbO 9 -Bi 2 MoO 6 -Rh) is improved by 7.76%, giving rise to a photocatalytic overall water splitting activity enhancement by a factor of 4.74. This strategy emphasizes the importance of interface regulation in promoting the transfer of photogenerated charge carriers in Aurivillius-type photocatalysts, providing an effective pathway for designing and fabricating high-performance photocatalysts.
研究领域:
材料科学
·
光催化
·
能源转换
✓ 已验证
DOI
高影响因子
Catalysis Science & Technology
·
2024
·Vol. 14
·期 9
·2452-2460
·
IF 4.4
Xiao Tan,Suitao Qi,Guangxu Cheng,Chunhai Yi,Bolun Yang
As the ideal NO removal technology, the biggest challenge associated with the direct catalytic decomposition of NO is the development of highly active deNOx catalysts at low temperatures. Herein, a composite metal catalyst, Rh(0.2)/NC-MnFe, was prepared via impregnation for the low-temperature direct decomposition of NO, which exhibited 99.6% NO conversion and 63% N2 selectivity at 150 °C, and nearly 100% NO conversion and 98% N2 selectivity at 200 °C. The characterization results showed that the Rh(0.2)/NC-MnFe catalyst possessed a regular nanocage structure, good crystallinity, and suitable specific surface area. Its excellent low-temperature activity was attributed to the transfer of the dissociated O of NO from the Rh active site to the NC-MnFe support, which effectively inhibited the deactivation of Rh. The mechanism analysis indicated that NO adsorbed on the Rh(0.2)/NC-MnFe catalyst surface can generate NO2− and NO3−, and then the adsorbed NO together with NO3− is converted to NO2− species accompanied by the release of N2O. At last, NO2− is decomposed to N2.
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
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Guangjun Ji,Cunyao Li,Benhan Fan,Guoqing Wang,Zhao Sun,Miao Jiang,Lei Ma,Li Yan,Yunjie Ding
Rational designing the structure of catalysts is an effective but challenging way to optimize catalytic performance for target reaction, which is especially significative in the field of single site catalysts. In this work, a kind of single Rh catalysts for heterogeneous hydroformylation of olefins with CO 2 as substituted carbonyl sources was designed. By simply doping N sites surround Rh P active sites, Rh 1 /POPs-P&N were endowed with better catalytic performance even than homogeneous Rh P complex catalysts. Our study showed that the fine fabricated skeleton structure of Rh 1 /POPs-P&N could endow the N sites with function promotion effect on the adjacent Rh P active sites to different degrees. Consequently, the Rh 1 / m -POP-PPh 3 &PMPD, which formed more HRh(CO) 2 (P) 2 species during the reaction, exhibited the highest yield of aldehydes (conversion of 89 %, selectivity toward aldehydes of 87.1 %, l/b ratio of 13.1), good stability (5 recycling runs without activity loss) and extensive substrate applicability (12 kinds of olefins) in heterogeneous hydroformylation of olefins with CO 2 , surpassing all homogeneous and heterogeneous catalysts that only contain Rh P sites (Table 5). Multiple characterization techniques (EXAFS, STEM, in-situ FTIR etc. ) were employed to get insights into this effective strategy to rationally design efficient single site catalysts.
研究领域:
催化
·
材料科学
·
化学反应工程
·
无机化学
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2021
·
IF 5.816
Junji Chen,Mengqin Yao,Qizhuang Zou,Peng Chen,Fei Liu,Tianxiang Zhao
An effective strategy synthesis of Rh/meso-Al 2 O 3 catalysts was demonstrated by mechanochemistry for hydrolytic dehydrogenation of ammonia borane (AB). These catalysts are characterized systematically by N 2 adsorption-desorption isotherms, X-ray diffraction (XRD), X-ray photoelectron spectrometry (XPS), scanning electron microscope (SEM), and transmission electron microscope (TEM). The results show that the turnover frequency (TOF) and activation energy ( E a ) are 246.8 mol H2 ·mol Rh −1 ·min −1 and 47.9 kJ mol −1 for hydrolytic dehydrogenation of at 298 K catalyzed by Rh/Al 2 O 3 -CTAB-400, obviously higher than those previously reported catalysts. Furthermore, catalyst Rh/Al 2 O 3 -CTAB-400 can be recycled by simple centrifugal separation and the catalytic activity is still well maintained after five cycles. In addition, a plausible mechanism for hydrolytic dehydrogenation of AB has also been proposed. This mechanochemical synthesis method exhibits great application prospects for the preparation of heterogeneous catalysts .
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 Science & Technology
·
2024
·Vol. 14
·期 10
·2722-2729
·
IF 4.4
Yuqiao Li,Dezheng Li,Huimin Liu,Yiming Lei,Rongda Zhao,Dehua He,Ze Zheng,Hui Luo,Aidi Liu
Photothermal dry reforming of methane (DRM), as an emerging branch of heterogeneous catalysis, could effectively convert CO2 and CH4 into high-value-added chemicals via the synergistic effect between thermochemical and photochemical processes. Herein, we report that loading Rh nanoparticles (NPs) on Ga2O3−x with oxygen vacancies improves CO2 conversion efficiency through photo-assisted DRM. On the Rh/Ga2O3−x catalyst, the photothermal catalytic CO2 conversion rate (112.0 μmol g−1 min−1) is 1.6 times that of the thermal reaction at 500 °C (71.9 μmol g−1 min−1). Rh2O3 and Ga2O3 as precursors are in situ reduced to Rh NPs and Ga2O3−x under the reductive DRM reaction atmosphere, respectively. Characterization results indicate that Rh NPs accelerate the DRM process by enhancing light absorption ability and charge transfer efficiency. Meanwhile, the oxygen vacancies in Ga2O3−x are beneficial for activating reactant molecules rapidly. In situ DRIFTS spectra showed that Rh NPs and oxygen vacancies served as reduction and oxidation sites during the photothermal DRM process. This work paves the way for the rational design of better photothermal catalysts in the future.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Jian Du,Xilong Wang,Chao Li,Xin-Yu Liu,Lin Gu,Han-Pu Liang
Studies on highly effective electrocatalysts for producing hydrogen via electrochemical water splitting is of great significance due to the increasing demand of clean and sustainable hydrogen energy economy. In this work, hollow RhCo nanoparticles with an average diameter of 21 nm were fabricated using the galvanic replacement method in a water-ice bath. Electrochemical evaluation showed that the as-synthesized electrocatalyst exhibited better performance for hydrogen evolution reaction (HER) under acid condition, with a lower overpotential of 28.1 mV at 10 mA cm −2 and a lower Tafel slope of 24 mV dec −1 , in comparison with commercial Rh/C. The better HER performance of the as-prepared hollow Rh nanoparticles could be attributed to the larger surface area than commercial Rh nanoparticles, which could provide more active sites and therefore improve the electrocatalytic performance.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）