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
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Jianian Chen,Mingyu Chu,Fenglei Lyu,Jin Gong,Linzhong Wu,Lijia Liu,Yong Xu,Qiao Zhang
Two-dimensional (2D) metal carbides, carbonitrides, and nitrides (MXenes) have recently emerged as promising candidates in catalysis due to their unique properties. In this work, we composited Ti3C2 with Co-embedded N-doped carbon nanotubes (CNTs) via the pyrolysis of zeolitic imidazolate frameworks (ZIF-67) for propyne selective hydrogenation. Detailed characterizations show that strong synergistic effects are observed between the Ti3C2 and Co-embedded N-doped CNTs in the composite catalysts. This work provides an efficient strategy to achieve N-doping on Co nanoparticles, which play a vital role in the propyne selective hydrogenation. The optimized catalyst gives a high propyne conversion (∼99%) and high propene selectivity (∼96%) on propyne selective hydrogenation at 150 °C, which surpasses the reported non-noble metal catalysts in literature works. This work may not only open an avenue for obtaining active and selective catalysts for propyne selective hydrogenation but also promote research on the role of MXenes in catalysis.
研究领域:
化学工程
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材料科学
·
催化
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2020
·Vol. 150
·期 7
·2045-2055
·
IF 2.482
Li Chaoqun,Yang Yang,Ren Wei,Wang Jian,Zhu Tingyu,Xu Wenqing
Abstract CO is toxic and detrimental to human beings and the atmosphere. The presence of CO has become one of the important indicators for evaluating ambient air quality. Iron and steel sintering generate large amounts of flue gas emissions containing approximately 1% CO, which has become an important factor restricting the improvement of air quality in steel cities. The catalytic oxidation method is the simplest and most effective method for CO emission control. In this work, a series of Cu x Ce y /TiO 2 catalysts with different Ce doping levels were prepared by a one-step impregnation method and subsequently tested for catalytic CO oxidation. The Cu 0.5 Ce 0.5 /TiO 2 sample has the best catalytic activity under the conditions of 1% CO and 10% H 2 O. The catalysts were next characterized by XRD, BET, TEM, H 2 -TPR, XPS and in-situ DRIFTS methods. The characterization results show that Ce doping promotes the dispersion of copper species on the catalyst surface and improve the redox performance of the catalyst. The results of in-situ experiments showed that both Cu/TiO 2 and Cu 0.5 Ce 0.5 /TiO 2 catalysts followed Mars and van Krevelen mechanism, and Ce doping enhanced the adsorption and activation of oxygen, thus improving the low-temperature reaction activity of the catalysts. Graphic Abstract
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2017
·
IF 9.446
Wenhui Li,Xiaowa Nie,Xiao Jiang,Anfeng Zhang,Fanshu Ding,Min Liu,Zhongmin Liu,Xinwen Guo,Chunshan Song
Screening of various supports reveals that Co catalysts supported on ZrO 2 and Al 2 O 3 show good initial activity for CO 2 methanation. Co/ZrO 2 and Co/Al 2 O 3 catalysts prepared by impregnation with different metal loadings were further examined comparatively. The 10Co/ZrO 2 catalyst showed high activity with CO 2 conversion of 92.5% and CH 4 selectivity of 99.9% without deactivation after 300 h time on stream (TOS). However, the 10Co/Al 2 O 3 catalyst gave a lower CO 2 conversion of 77.8% which decreased to 38.6% after 300 h TOS. The catalysts were characterized by STEM/EDS (scanning transmission electron microscopy/energy-dispersive X-ray spectroscopy), in situ XRD(X-ray diffractometer), H 2 -TPR(temperature programmed reduction), XPS (X-ray photoelectron spectroscopy), chemisorption of H 2 , CO, CH 4 , CO 2 and NH 3 -TPD (temperature programmed desorption). Re-dispersion of Co species on the ZrO 2 support during reduction by H 2 was observed by STEM/EDS. New Co-Zr phase formed on the Co-ZrO 2 interface was directly observed by TEM for the first time; the Co/ZrO 2 catalyst exhibited high stability with high activity for CO 2 conversion. In situ XRD, H 2 -TPR and XPS results indicate the promoting effect of ZrO 2 on the reduction of Co 3 O 4 to Co metal along with the negative effect of Al 2 O 3 . The oxygen vacancies on the ZrO 2 detected by XPS may help to activate CO 2 and H 2 O and resist deactivation. Co/Al 2 O 3 catalyst deactivates rapidly due to coke deposition and spinel formation.
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
Energy Materials
·
2024
·Vol. 4
·期 6
·N
·
IF 11.8
Zuwei Xu,Ze Zhang,Fuchang Gao,Yuhan Zhu,Haibo Zhao
Catalytic combustion is an effective approach to remove air pollutants from various emission sources. For this purpose, supported noble metal catalysts are preferred in commercial applications due to their outstanding catalytic activity for eliminating CO, hydrocarbon compounds and NOx. In this paper, we employ the flame spray pyrolysis method to prepare a series of Pt-based catalysts with four different supports (TiO2, ZrO2, MgO and ZnO) and variable low Pt loadings for catalytic combustion of CO and CH4. The performance of 0.5 Pt/TiO2 is the best in all samples, in which the T90 temperatures are 107 and 500 °C for 90% conversion of CO and CH4, respectively. To examine its thermal stability, a time-on-stream test at 700 °C for 420 min is carried out, resulting in a decrease of about 5% in the final conversion of CH4. The X-ray diffraction results show that TiO2 support is a mixed phase with a major amount of anatase and a small amount of rutile other than a pure phase of ZrO2, MgO and ZnO. Furthermore, X-ray photoelectron spectroscopy analysis and high-angle annular dark-field scanning transmission electron microscopy observation show that when the Pt loading is low, the Pt species exist as highly dispersed single atoms on the surface of the TiO2 support. As the Pt loading gradually increases, the state of the Pt species transitions from single atoms to Pt clusters, resulting in a decrease in dispersion. Ultimately, the Pt can successfully accumulate on the surface of the TiO2 nanoparticles, providing abundant active sites for efficient catalytic combustion reactions.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
NEW CARBON MATERIALS
·
2021
·
IF 1.905
Jing Zhang,Lianghao Song,Chenfei Zhao,Xiuping Yin,Yufeng Zhao
Although the Co and N co-doped carbon catalyst (Co-NC) has attracted much attention because of its low cost and the natural abundance of the dopants, it has a low oxygen reduction reaction (ORR) activity and a high selectivity for the two-electron (2e - ) reduction of oxygen to H 2 O 2 , which affects its use in fuel cells. Co-NC catalysts were prepared by the pyrolysis of a mixture of cobalt chloride and chitosan pretreated with zinc chloride at 650, 750 and 850 o C, followed by washing with nitric acid and annealing at 900 o C. The results indicate that zinc chloride helps the complexing of chitosan with Co 2+ , which is also a chemical activator that generates pores, and annealing caused the evaporation of the spherical Zn metal nanoparticles formed by the carbothermal reduction of Zn ions, leading to a unique porous structure of the catalysts with spherical pores filled with spherical carbon nanoparticles formed by the growth of nitrogen-doped carbon as a result of the Co catalyst. The degree of graphitization is also improved by the Co catalyst. The Co-NC catalyst obtained at a pyrolysis temperature of 750 o Cshows the same four-electron (4e - ) reduction of oxygen as a commercial Pt/C catalyst, and a significantly higher ORR catalytic activity, longer-term stability and better methanol tolerance than a commercial Pt/C catalyst. These are due to its large specific surface area, high contents of pyridinic nitrogen and graphitic nitrogen that disperse the Co species and its excellent electrical conductivity.
研究领域:
材料科学
·
电化学
·
催化
·
能源材料
✓ 已验证
产品关联
DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2016
·
IF 2.848
Huan Liu,Yi Lin,Zhen Ma
Au/M-P-O (M = Mg, Al, Ca, Fe, Co, Zn, La) catalysts were prepared by loading ca. 1 wt.% gold onto commercial metal phosphate supports by deposition-precipitation with urea (DPU), and tested in CO oxidation. Au/La-P-O showed the highest activity, achieving complete CO conversion at 70 °C. Au/Ca-P-O was the second most active, achieving complete CO conversion at 155 °C. The remaining catalysts were not active below 200 °C. In view of the results, we additionally prepared Au/LaPO 4 nanowires by loading ca. 1 wt.% gold onto LaPO 4 nanowires via DPU. The Au/LaPO 4 nanowires catalyst was even more active, achieving complete CO conversion at 15 °C. The catalysts were characterized by N 2 adsorption-desorption, inductively coupled plasma optical emission spectroscopy (ICP-OES), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and temperature-programmed desorption of O 2 or CO 2 (O 2 -TPD, CO 2 -TPD). Reasons for the higher activity of Au/LaPO 4 nanowires were discussed.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Xing Yuan,Lingquan Meng,Chaohe Zheng,Haibo Zhao
Perovskites have been recognized as affordable substitutes for noble-metal catalysts for their tunable catalytic activity and thermal stability. Nevertheless, the highly demanding synthesis procedure still hinders the application of perovskites in catalytic combustion. In this work, a series of nanostructured SiTiO3 perovskites with B-site partial substitution by Co, Fe, Mn, Ni, and Cu are synthesized via flame spray pyrolysis in one step. The comprehensive characterizations on textural properties of nanostructured perovskites reveal that the flame-made perovskite nanoparticles all exhibit high crystal purity and large specific surface area (∼40 m2/g). Furthermore, the highest catalytic activity is achieved by SrTi0.5Co0.5O3 due to the formation of favorable oxygen vacancies, outstanding reducibility, and oxygen desorption capability. Additionally, the presence of 10 vol % water vapor during long-term testing indicates remarkable durability and water resistance. Finally, the CO oxidation and CH4 dehydrogenation on SrTiO3 incorporating Co atoms are more thermodynamically and kinetically favorable than those on other doped surfaces.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Yiqun Chen,Xiaori Huang,Dedong Sun,Hongchao Ma,Guowen Wang,Chun Ma,Jun Hao
In this study, the Fe 3 O 4 /Co 3 [Co(CN) 6 ] 2 composite catalyst was synthesized by co-precipitation method. The morphology and the structure of Fe 3 O 4 /Co 3 [Co(CN) 6 ] 2 composites were characterized by XRD, FTIR, SEM, TEM, EDS, XPS, VSM. The results showed that the removal rate of RhB (10 mg/L) reached 99.5% in 40 min in the 0.4-Fe 3 O 4 /Co 3 [Co(CN) 6 ] 2 (200 mg/L) + PMS (50 mg/L) system with a pseudo first-order degradation rate constant (k) of 0.121 min −1 , which is nearly 2.16 times of that (0.0561 min −1 ) in the Co 3 [Co(CN) 6 ] 2 + PMS system and 18.9 times of that (0.0064 min −1 ) in the Fe 3 O 4 + PMS system. The observed synergistic catalysis between Fe 3 O 4 and Co 3 [Co(CN) 6 ] 2 in Fe 3 O 4 /Co 3 [Co(CN) 6 ] 2 enhanced the degradation of RhB. The electron paramagnetic resonance (EPR) analysis and quenching experiment indicated that SO 4 − and OH played important roles in the degradation process of RhB. A synergistic catalytic mechanism of PMS activation by Fe 3 O 4 /Co 3 [Co(CN) 6 ] 2 , which mainly involves the enhanced Co 2+ /Co 3+ cycle by Fe 2+ donated electrons, was proposed. In summary, owing to its easy preparation, excellent catalytic activity, and reusability, the Fe 3 O 4 /Co 3 [Co(CN) 6 ] 2 composite catalyst is a good candidate for remediation of contaminated water.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2024
·
IF 3.9
Xingling Zhao,Xue Zhou,Wanyan Xing,Zhimin Yuan,Kaili Wang,Qihang Zhang,Yulong Shan,Jiani Liu,Lin Ju,Zaiyong Jiang,Hong He
CO is a ubiquitous air pollutant, frequently encountered in the fields of automotive exhaust purification, especial in the cold-start-emission stage. Pt based catalysts are widely used to purify CO into CO 2 owing to their exceptional performance. But they can be few excited to exhibit reasonable catalytic activity due to the low temperature at the cold-start-emission stage. In exhaust gas purification catalysts used by fossil fuel-based vehicles, Al 2 O 3 is used frequently. But there are rarely reports of Pt loaded Al 2 O 3 catalysts achieving feasible activity of CO oxidation at room temperature. Herein, we prepared Cu x Pt y alloy/Al 2 O 3 catalysts (with high penta-coordinated Al 3+ (Al V )), Al V centers as binding sites for Cu 3 Pt 1 alloys on Al 2 O 3 enable the high dispersion and stability of Cu 3 Pt 1 alloy. The adsorption capacity of O 2 and CO molecules on Cu 3 Pt 1 surface are stronger than the case on Pt surface, which may make O 2 and CO molecules more easily activated, making the CO oxidation reaction easier. In addition, the desorption of CO 2 from Cu x Pt y surface is easier compared to that on Pt surface, increasing the frequency of use of active sites there. Therefore, this Cu 3 Pt 1 /Al 2 O 3 catalyst exhibits 100 % conversion of CO with a GHSV of 6×10 3 mL·g −1 cat ·h −1 at room temperature. This work provides a feasible guideline for the design and synthesis of Pt loaded Al 2 O 3 catalysts toward room temperature CO oxidation.
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
SYNTHETIC METALS
·
2025
·
IF 4.6
Yu Lin,Gen Li,Juan Teng,Haibo Wang,Ximei Liu
As a crucial component of flexible electronic devices, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)-based hydrogels for strain sensors have garnered extensive attention for their potential in the field of wearable sensors due to their inherent conductivity and flexibility. However, challenges such as poor mechanical strength, limited sensitivity, and poor durability have hindered the widespread application of PEDOT:PSS hydrogels in high-performance strain sensors. In this study, we develop a novel PEDOT:PSS-P(HEMA-co-AA) hydrogel that addresses common limitations in hydrogel applications, demonstrating remarkable stretchability, low hysteresis, and reliable conductivity. The hydrogel is synthesized using a semi-interpenetrating polymer network (SIPN) strategy, combining the linear conducting polymer PEDOT:PSS with a chemically cross-linked network based on 2-hydroxyethyl methacrylate (HEMA) and acrylic acid (AA). This hybrid structure notably contributes to the hydrogel's mechanical properties, achieving a stretchability of 195 %, while maintaining a rapid response time of 0.20 seconds and exceptional cyclic stability over 1000 cycles under 100 % strain. Moreover, the hydrogel demonstrates promising strain-sensing capabilities, positioning it as a strong candidate for future applications in wearable electronics and flexible sensors. The adoption of the SIPN strategy, along with the synergistic combination of PEDOT:PSS and P(HEMA-co-AA), paves a new pathway for enhancing the mechanical performance and sensing properties of hydrogels in strain-sensing technologies.
研究领域:
材料科学
·
柔性电子
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2016
·
IF 2.725
Luanluan Zhang,Hejun Gao,Yunwen Liao
A series of functional cross-linked polymer (Poly(AMPS- co -DVB)) were synthesized by 2-acrylamido-2-methylpropane sulfonic acid (AMPS) and divinylbenzene (DVB). The physicochemical properties of the Poly(AMPS- co -DVB) were characterized by FT-IR, TGA , SEM, XRD , Zeta potential and UV–Vis. Those results showed that the Poly(AMPS- co -DVB) could provide mounts of adsorption sites from its special structure. The effects of the initial pH, dosage, contact time, and temperature on the adsorption of Rhodamine B (RhB) onto the Poly(AMPS- co -DVB) were investigated. It was found that the initial pH was an important factor for the molecules form of RhB and the surface formation of Poly(AMPS- co -DVB). With increasing of molar ratio of AMPS/DVB, the adsorption efficiency increased gradually. In the adsorption process , both physical and chemical mechanism is presence to adsorb RhB. The maximum adsorption capacity could get 407.9 mg/g within 2 h at room temperature .
研究领域:
环境科学
·
材料科学
✓ 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）