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
Journal of CO2 Utilization
·
2020
·
IF 5.993
Chengyi Dai,Xiao Zhao,Borui Hu,Xinbao Zhang,Qunxing Luo,Xinwen Guo,Xiaoxun Ma
Capturing and utilization of carbon dioxide (CO 2 ) not only leads to effective use of carbon resources, but also alleviates environmental pollution caused by increasing concentration of CO 2 , thus making it a hot research topic in recent years. In this study, a series of highly dispersed iron-cobalt (Fe-Co) catalysts was prepared by ethylenediaminetetraacetic acid disodium salt (EDTA-2Na) modification, which could efficiently convert CO 2 into high value-added chemicals (C 2 -C 4 = and C 5 -C 11 ). X-ray diffraction (XRD) analysis showed that the addition of a small amount of Co and EDTA-2Na contributed to enhance the sintering resistance of Fe species. During the calcination process, EDTA 4− can be decomposed into small organic molecules with reducibility, thus promoting the reduction of iron species. The CO temperature-programmed desorption (CO-TPD) results showed that cobalt enhanced the adsorption and activation of intermediate CO on Na x Fe-Co catalyst, thereby promoting the catalytic conversion of CO 2 . The complexation of EDTA promotes the synergistic effect of Fe-Co bimetals, enhances the chemical adsorption of CO 2 . Sodium in EDTA-2Na promotes the surface basicity of the catalysts, which is favored for improving the product distribution of hydrocarbons. At lower H 2 /CO 2 (1/1) ratio, the EDTA-2Na modified Fe-Co/Al 2 O 3 catalyst exhibited high conversion of CO 2 (32.8 %) and excellent selectivity toward high value-added chemicals. The selectivity of by-product CO was only 8.1 %; and C 2 -C 4 = (32.5 %) and C 5 -C 11 (46.3 %) accounted for ∼79 % selectivity among the hydrocarbons generated.
研究领域:
催化化学
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环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2021
·Vol. 168
·期 9
·090512
·
IF 4.316
Yuebing Wang,Dunpeng Yang,Aling Chen,Qingfeng Yi
The development of an efficient, stable and low-cost cathode catalyst is necessary for the practical application of Zn-air batteries. In this paper, Fe3+/Co2+ ions were in situ incorporated into polydopamine during the polymerization of dopamine on the surface of the SiO2 spheres. After subsequent pyrolysis and leaching SiO2, the products loaded with different metals (NHCS-Fe, NHCS-Co, NHCS-Fe1Co0.6, NHCS-Fe1Co4, NHCS-Fe1Co10) were obtained. The samples possess a typical hollow carbon sphere (HCS) structure and show efficient oxygen reduction reaction (ORR) performance under neutral and alkaline conditions. Especially in the neutral electrolyte, the NHCS-Fe exhibits the comparable electrochemical catalytic activity to the commercial Pt/C. For NHCS-Fe, its ORR half-wave potential in neutral and alkaline media is 0.78 V and 0.83 V respectively. Corresponding neutral Zn-air battery reveals a maximum power density of 118.8 mW·cm−2, while they are respective 0.82 V and 46.99 mW·cm−2 for Pt/C. Alkaline Zn-air battery with NHCS-Fe releases a maximum power density of 262.4 mW·cm−2, displaying superior performance to Pt/C. Our work is instructive for the synthesis of novel ORR catalysts with outstanding activity by a versatile synthesis strategy.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
CARBON
·
2017
·
IF 6.337
Lei Tang,Yuting Luo,Shuchen Zhang,Qichong Zhang,Yagang Yao,Jin Zhang
A novel substrate-anchored catalyst, solid solution, was developed, which experienced the annealing treatment of the single crystal MgO substrates with Co species deposited. The formation of specific structure on MgO surface and sub-surface makes Co catalysts anchored. Subsequent H 2 reduction treatment continuously released fresh active catalysts from this anchored special structure for SWNTs nucleation and growth. This gradual releasing behavior provides more catalytic opportunities to nucleate and realizes high density SWNTs growth.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2020
·Vol. 22
·期 19
·6579-6587
·
IF 9.48
Xiaohao Liu,Xiaodong Liu,Haiyong Wang,Tianci Xiao,Ying Zhang,Longlong Ma
Efficient conversion of renewable cellulose to high value-added C3 chemicals is a great challenge in the field of biomass valorization. In this work, we found that the combination of Co and Sn could significantly improve the efficiency of cellulose conversion to acetol. 54.4% yield of acetol and 66.6% total yield of C3 products were obtained when using 2%Sn–10%Co/SiO2 (2 wt% Sn content) as a catalyst. However, using the same Sn content of 2%Sn–10%Ni/SiO2, no acetol and only 7.1% yield of C3 products were produced. By studying the effects of different Sn and Co concentrations on cellulose conversion, it was found that the Sn species play an important role in catalyzing glucose conversion to C3 intermediates, while Co mainly played a role in hydrogenation, the same as Ni. The study demonstrated that Sn–Co/SiO2 with low Sn content can convert glucose to C3 intermediates more efficiently than the Sn–Ni/SiO2 catalyst. Moreover, Sn–Co/SiO2 could effectively convert C3 intermediates to acetol at a high temperature which is essential for acetol production from cellulose; but under the same conditions, the Sn–Ni/SiO2 catalyst tended to catalyze the polymerization of C3 intermediates. A series of characterization methods including AAS, TEM, HRTEM, EDS, XRD, ex situ XPS, in situ XPS, and CO2-TPD found that the combination of Sn and Co could significantly increase the noninteger valent SnOx species in the catalyst. These species increased the basicity of the catalyst and were beneficial in catalyzing the isomerization of glucose and the retro-aldol condensation of fructose.
研究领域:
生物质能
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Ying Xiong,Yumei Zhao,Weijun Shan,Xiaogeng Feng,Junshuo Cui,Zhenning Lou,Guoxiang Shao,Min Dong,Haibiao Yu
In order to enhance the catalytic performance of the Gd-modified Co 3 O 4 catalyst (Gd 0.06 Co) for the N 2 O decomposition, alkali metal K was introduced as the promoter by impregnating the Gd 0.06 Co powder with an aqueous solution of KNO 3 (with K/Co ratios 0.01–0.05). With the doping of K, the catalytic activity over Gd 0.06 Co was significantly improved and the temperature of N 2 O complete decomposition was decreased from 350 °C to 300 °C. Combining the results of XPS and O 2 -TPD, the superior catalytic performance of the optimum catalyst K 0.025 Gd 0.06 Co was mainly owing to the synergistic effect of Gd and K, which weakened the Co–O bond and endowed the catalyst surface with much more amount of oxygen vacancies. Even under the coexist of the impurity gases, such as 5 vol% O 2 , 100 ppmv NO and 2 vol% H 2 O, the K 0.025 Gd 0.06 Co catalyst exhibited prominently better catalytic activity than Gd 0.06 Co and K 0.025 Co catalysts.
研究领域:
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACTA PHYSICO-CHIMICA SINICA
·
2017
·Vol. 33
·期 8
·1672-1680
·
IF 0.767
LIAO Pei-Yi,ZHANG Chen,ZHANG Li-Jun,YANG Yan-Zhang,ZHONG Liang-Shu,GUO Xiao-Ya,WANG Hui,SUN Yu-Han
A series of Cu/Co/Mn/Al catalysts derived from hydrotalcite precursors with different Cu/Co molar ratios (0, 0.1, 0.5, 1.0, and 2.0) were prepared and used for the synthesis of higher alcohols from syngas. N2 physical adsorption desorption, inductively coupled plasma atomic
emission spectrometry (ICP-AES), X-ray diffraction (XRD), scanning electron microscopy (SEM), hydrogen temperature-programmed reduction (H2-TPR), thermogravimetry (TG), and high-resolution transmission electron microscopy (HRTEM) techniques were employed to investigate the physical
and chemical properties of the Cu/Co/Mn/Al catalysts. The results show that the optimum Cu content can increase specific surface area, improve reducibility, and form regular layered structure to provide more uniform distribution of active sites, thereby enhancing catalytic activity and alcohol
selectivity. When the Cu/Co molar ratio was 0.5, the yield of alcohol and the alcohol selectivity reached the maximum values of 0.071 g·g-1·h-1 and 35.9%, respectively.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2024
·
IF 11.2
Hongguang Zhang,Ying Zhu,Furui Hu,Wuxiang Zhang,Fuzheng Fu,Tao Gan,Zuqiang Huang,Huayu Hu,Yanjuan Zhang
ABSTRACT Water-assisted proton hopping (WAPH) plays an important role in the aqueous-phase hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL). In this study, based on a strategy of spontaneously polarized ceramic (SPCE)-reinforced WAPH, a Ni–Co/SPCE–C catalyst was constructed by high-temperature calcination of a dual mechanical activation-treated precursor. Ni–Co/SPCE–C with favorable structural characteristics, intimate interfacial compatibility, and unique spontaneous polarization effect enhanced the migration efficiency of active hydrogen and activated water to form small water clusters, contributing to outstanding catalytic activity for aqueous-phase hydrogenation of LA to produce GVL at relatively low reaction temperature and H 2 pressure. A LA conversion of 99.9% and a GVL yield of 92.3% were achieved at 160°C and 1.5 MPa H 2 over the Ni–Co/SPCE–C catalyst, which were significantly higher than those catalyzed by contrastive catalysts. A variety of tests and theoretical calculations reveal that SPCE with far-infrared emission and surface electric field was conducive to the reduction in the hydrogen spillover energy barrier, the stabilization of the transition state, and the facile exchange of H 2 and water for accelerating WAPH. Moreover, a reasonable SPCE-reinforced WAPH mechanism was proposed to explain the enhanced aqueous hydrogenation of LA. This research can provide valuable insights into the design and development of high-performance non-noble metal catalysts for aqueous hydrogenation applications.
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
CHEMISTRY-A EUROPEAN JOURNAL
·
2022
·Vol. 29
·期 16
·e202203142
·
IF 5.02
Jingwen Luo,Anqi Huang,Yao-Yue Yang,Xing-Yu Ma,Quan-Liang Chen,Junxian Chen,Yajuan Wu
Graphical Put to good use : A Pd-doped Co (Pd/Co) catalyst with high Pd atom utilization efficiency was designed and prepared for hydrogenation of nitroarenes. Its catalytic activity was much better than commercial Pd powder (>150 times) in nitrobenzene hydrogenation reaction. This work might provide a simple and low-cost methodology to design and synthesize highly efficient catalysts. Enhancing catalytic performance as well as reducing catalyst cost are the eternal pursuit for the catalysis community. Herein, a simple and effective palladium-doped cobalt (Pd / Co) catalyst with high Pd atom utilization efficiency was synthesized via galvanic replacement reaction for the selective hydrogenation of nitrobenzene with H 2 at room temperature, delivering >99 % yield of aniline with up to 158 times higher catalytic activity than commercial palladium powder. Detailed characterizations and DFT calculations revealed that Co−Pd interaction leads to a decrease in electron density of Pd and the distance between Pd atoms that results in the enhanced catalytic performance. Further experiments indicated that the Pd / Co catalyst serves as a highly efficient, selective, and recyclable catalyst for a range of nitroarene substrates. This work might provide a green and sustainable methodology to design and synthesize highly active catalysts with high utilization efficiency of the noble metals in fundamental and applied research.
研究领域:
催化化学
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材料科学
·
理论计算化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 19
·11843-11852
·
IF 4.036
Qi Guo,Xinglong Hou,Wei Xu,Junli Liu
Ni3Co1/ELAC catalyst, prepared by the enzymatically hydrolyzed lignin activated carbon as a carrier and a 3 : 1 ratio content of nickel and cobalt, can selectively convert furfural to cyclopentanol (CPL) in aqueous solution. We used activated carbon prepared by the phosphoric acid method as the carrier, and investigated the effect of the carrier on the catalyst activity. The ratio of bimetal (Ni, Co) content and reaction conditions (reaction temperature, reaction time, initial H2 pressure) have also been investigated in the furfural hydrogenation. With the optimal Ni3Co1/ELAC catalyst, the conversion rate of furfural and the selectivity of CPL were 100% and 94.1%, respectively. In this process, some important catalysts were studied by XRD, XPS, ICP-AES, BET and TEM characterization. Through experimental results and other people's research, we deduced a reasonable reaction path and verified it by replacing the reaction substrate and solvents. Finally, the experiment proved that the formation of CPL by furfural required the occurrence of a rearrangement reaction and the participation of aqueous solution.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Surfaces and Interfaces
·
2024
·
IF 5.7
Suiqi Zhu,Changchun Ye,Yifei Li,Yanan Chong,Tingyu Chen,Jin Yang,Mingli Fu,Keyou Yan,Yongcai Qiu
The construction of hybrid nanocatalysts with enhanced active surfaces/interfaces is crucial for the catalytic oxidative removal of volatile organic compounds (VOCs). In this study, we report an in-situ conversion approach to synthesize a heterostructured Co 3 O 4 /Co catalyst (Co@NC-0.5) for efficient photothermal catalytic oxidation of acetone. The catalysts were prepared by pyrolyzing a mixture of ZIF-67 and melamine. The exposed cobalt species underwent in-situ oxidation to form a Co 3 O 4 /Co heterostructure under photothermal conditions. This unique catalyst structure exhibited over 90 % conversion within 16 min under full solar spectrum irradiation and excellent reusability with continuous maintenance of 100 % acetone conversion rate after nine cycles performance tests. Notably, its specific mass activity under thermocatalytic conditions was 2.13 times higher than that of Co 3 O 4 . Our work provides a facile and effective strategy for developing highly active and durable non-precious metal catalysts suitable for various photothermal catalytic reactions.
研究领域:
材料科学
·
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
Shiyi Wang,Mingsheng Luo,Zhi Yang,Ziyang Zhang,Wenshuai Yang,Ziyuan Li,Xiaoteng Cui,Lingman Xia,Changke Shao
Using a citrate-assisted liquid phase co-precipitation method, a CuCoAl-LDH composite nanomaterial was successfully synthesized in situ on rGO and applied to alcohol synthesis for the first time. Structural characterization and morphological observations indicate that the hybrid material consists of hexagonal LDH nanosheets that are vertically aligned, crossed and densely distributed on the rGO surface. The graphene support significantly promoted the dispersion of LDH and prevented strong interlayer stacking during LDH crystal growth. After optimization of the Co/Cu ratio, the Cu 2 Co 1 /Al 2 O 3 /rGO catalyst exhibited a total alcohol selectivity of 60 %, of which 82 % were C 2+ alcohols, and no deactivation was observed after 100 h of reaction. The addition of the graphene support significantly reduced the particle size of the Cu-Co alloy on the catalyst surface, and the particles were highly dispersed on both the Al 2 O 3 matrix and the rGO surface. This dispersion facilitated strong interactions between the Cu-Co alloy particles, while the high thermal conductivity of graphene effectively suppressed the formation of hotspots. In addition, the well-ordered three-dimensional nanosheet structure of the LDH precursor provides a large specific surface area and highly uniformly dispersed active centers. This structure not only promotes the formation of bridge adsorption sites with high CO dissociation ability, which balances multiple bonding and bridge CO adsorption, but also significantly increases the probability of CO insertion, thereby enhancing the performance of HAS. This study provides an effective method for the preparation of LDH/rGO composites, demonstrating their broad potential application prospects.
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
危险品化学品经营许可证（带存储）