APPLIED CATALYSIS A-GENERAL
·
2026
·
IF 4.8
Yu Han,Yu-Wei Xiang,Zhi-Rong Fu,Xin Zhang,Jia-Yi Zhou,Xiang-Sen Wu,Yong Luo
The 8H-NEC was synthesized by different organic routes and used as the substrate for kinetic studies. • Ru/Al 2 O 3 catalysts with controllable Ru particle sizes were prepared. • Smaller Ru particles showed higher TOF and lower apparent activation energy. • Low-coordinated Ru line-edge sites enhanced 8H-NEC adsorption. N -ethylcarbazole (NEC) is a promising liquid organic hydrogen carrier (LOHC) for hydrogen storage, and Ru/Al 2 O 3 catalyst is one of the most widely used catalysts for NEC hydrogenation. However, previous studies have primarily focused on the chemical electronic effect of Ru/Al 2 O 3 catalyst, while neglecting the influence of geometric structure. In this work, Ru particle size effect on the rate-determining step of 8H- N -ethylcarbazole (8H-NEC) hydrogenation has been considered. Firstly, a series of Ru/Al 2 O 3 catalysts with controllable Ru particle sizes were prepared. After that, 8H-NEC was synthesized by different organic routes to serve as the substrate for catalytic and kinetic experiments. Results showed that as the Ru particle size increased from 1.4 to 5.3 nm, the turnover frequency (TOF) decreased from 59.7 to 32.2 min −1 and the apparent activation energy increased from 44.55 to 74.00 kJ·mol −1 . CO probe diffuse reflection infrared Fourier transform spectrum (CO-DRIFTS) and density functional theory (DFT) results demonstrated that superior catalytic performance of smaller Ru particles was associated with the exposure of more low-coordinated line-edge sites, which exhibited stronger adsorption toward 8H-NEC. This study offers new insights into the design of highly efficient catalysts of NEC hydrogenation. Download: Download high-res image (169KB) Download: Download full-size image
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高影响因子
Nanoscale
·
2023
·Vol. 16
·期 1
·335-342
·
IF 6.7
Yinglei Liu,Chicheng Ma,Jiye Zhang,Huiying Zhou,Gaowu Qin,Song Li
The electronic interaction between a metal and a support modulates the electronic structures of supported metals and plays an important role in manipulating their catalytic performance. However, this interaction is mainly realized in heterogeneous catalysts composed of reducible oxides. Herein, we demonstrate the electronic interaction between γ-Al2O3 and η-Al2O3 with varying acid–base properties and supported Pd nanoparticles (NPs) of 2 nm in size. The strength and number of acid–base sites on the supports and catalysts were systemically characterized by FT-IR spectroscopy and TPD. The supported Pd NPs exhibit electron-rich surface properties by receiving electrons from the electron-donating basic sites on γ-Al2O3, which are beneficial for catalyzing the hydrogenation of nitrobenzene. In contrast, Pd NPs loaded on η-Al2O3 are electron-deficient because of the rich electron-withdrawing acid sites of η-Al2O3. As a result, Pd/η-Al2O3 exhibits higher catalytic activity in phenylacetylene hydrogenation than Pd/γ-Al2O3. Our results suggest a promising route for designing high-performance catalysts by adjusting the acid–base properties of Al2O3 supports to maneuver the electronic structures of metals.
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PubMed
高影响因子
Journal of Materials Research and Technology-JMR&T
·
2023
·
IF 6.4
Jingyi Chen,Ruyue Su,Xiaofei Zhai,Yaru Wang,Xiong Gao,Xueqin Zhang,Yanpeng Zhang,Yan Zhang,Sheng Liu,Rujie He
Ceramic microcomponents have a wide range of applications in microfluidic, sensors, etc. Stereolithography 3D printing technology provided a shortcut for the preparation of this small-size and complex component. With the development of device miniaturization, the existing stereolithography forms cannot meet the demand. To prepare smaller components, it is necessary to decrease the slice thickness ( C s ). But during the stereolithography 3D printing, ceramic is usually easy to over-cure, leading to the key issue in the stereolithography of ceramic microcomponents: the mismatching between the curing thickness ( C p ) and the slice thickness ( C s ). To solve the problem above, this paper started from the stereolithography mechanism of the ceramic/resin slurry and adjusted the matching relationship between C p and C s theoretically by adding a photoabsorber. Then, from the experiments, the influence of different content of photoabsorber (carbon black) on curing thickness, printing accuracy, and sintering accuracy, were studied. Al 2 O 3 ceramic microcomponents that met the design requirements were thus prepared. These results would help in the development of stereolithography 3D printing of ceramic microcomponents.
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高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2023
·Vol. 30
·期 48
·105685-105699
·
IF 5.8
Dong Pei,Shan Peipei,Wang Shuaijun,Ge Baosheng,Zhao Chaocheng
In this work, efficient Fenton strategy have been proposed for degradation of shale gas fracturing flow-back wastewater using the spherical Fe/Al 2 O 3 supported catalyst. Prior to actual fracturing fluid treatment, the typical model wastewaters such as p -nitrophenol and polyacrylamide were employed to evaluate the catalytic properties of prepared catalyst, and then Fenton treatment of the shale gas fracturing flow-back wastewater was performed on the self-assembled catalytic degradation reactor for continuous flow purification. Results showed that under the conditions of 0.25 mol L −1 impregnating concentration, pH 4, 50 g L −1 catalyst and 0.75 mL L −1 30% H 2 O 2 , the removal efficiency of p -nitrophenol and polyacrylamide reached 74% and 61%, respectively, while the COD removal of fracturing flow-back fluid was approximately 48% with the residual 88 mg L −1 COD, meeting the emission standards of the integrated wastewater discharge standard (GB 8978-1996, COD < 100 mg L −1 ). This work offers new alternatives for Fenton treatment of real wastewater by efficient and low-cost supported catalysts.
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PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Jiaji Yang,Xiongzhang Liu,Wei Gong,Tao Wang,Xian Wang,Rongzhou Gong
Developing high-temperature microwave absorption (MA) materials remains a challenge in the field of radar stealth. Here, we propose a design concept of meta-structure for temperature-insensitive and broadband MA. The three-phase TiB 2 /Al 2 O 3 /MgAl 2 O 4 composites are prepared to realize the temperature-insensitive MA properties, which is ascribed to the interaction of different components in terms of the electrical conductivity , dipolar polarization and interfacial polarization as temperature increases. On this basis, we design and fabricate a three-layer meta-structure composed of the SiO 2 ceramics as environmental adaptation layer, the patch-type and flat composites as MA layers. Compared with flat composites, the meta-structure can optimize its effective permittivity, thereby realizing enhanced MA properties at elevated temperatures. This meta-structure can realize a reflection loss (RL) less than −5 dB at 8.2–18.0 GHz in the temperature range of 25 °C to 1100 °C. The experiment matches well with the simulation. The temperature-insensitive and enhanced MA properties are attributed to the consequence of the combination of traditional absorbing materials and metamaterial structures.
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高影响因子
FUEL PROCESSING TECHNOLOGY
·
2021
·
IF 7.033
Zhong Ma,Guofu Liu,Yonggang Lu,Junfeng Wang,Hui Zhang
In chemical looping combustion , iron-based oxygen carriers often experienced serious phase segregation , which reduced the cyclic stability of the oxygen carriers. In this work, Fe 2 O 3 /Al 2 O 3 (FA) was doped with different metals (Sr, La and Ce) to improve the redox performance during cyclic reactions. The mechanism of dopants on FA was explored by experimental research and characterization analysis. The promotion effect of different dopants on the redox performance of FA followed the sequence: Sr > La > Ce. It was shown that the deactivation of Ce-FA and La-FA was obvious in 20 cycles. The results of 100 successive cycles indicated that the surface structure of Sr-FA remained stable and no sintering was observed. The Sr-FA achieved stable oxygen carrying capacity (4%) in 100 redox cycles. The characterization results indicated that the addition of Sr could effectively increase the concentration of oxygen vacancies , thus inhibiting the phase segregation of FA. The enrichment degree of surface Fe of FA, Sr-FA, La-FA and Ce-FA were 135.7%, 43.47%, 128.0% and 140.0%, respectively. The results of this study provide guidance for the preparation of iron-based oxygen carriers with high redox performance.
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高影响因子
ChemCatChem
·
2021
·Vol. 13
·期 19
·4133-4141
·
IF 5.686
Lina Zhang,Bangjie Zhang,Peng Xue,Jiwei Li,Zhun Zhang,Yanling Yang,Shuai Wang,Jingdong Lin,Honggang Liao,Yong Wang,Yali Yao,Shaolong Wan,Haifeng Xiong
Graphical Room temperature oxidation : Pretreatment methods affect the nature of the Pd species and the reactivity of Pd/Al 2 O 3 in formaldehyde oxidation at room temperature. The steam treatment (H 2 O/Ar) increased the metal Pd dispersion, and generated more active hydroxyl groups, leading to the enhanced reactivity in formaldehyde oxidation. A Pd/Al 2 O 3 nanocatalyst was pretreated at 750 °C in air, Ar or H 2 O/Ar, respectively. The effect of these different pretreatments on the active species and reactivity of Pd/Al 2 O 3 in formaldehyde oxidation at room temperature was investigated. The pretreatment was found to affect both the phase transformation of PdO to Pd metal and the Pd dispersion, leading to different catalytic performances. We found that the Pd/Al 2 O 3 nanocatalyst pretreated in both Ar and H 2 O/Ar show 60 % and 100 % formaldehyde conversion at 25 °C, respectively, while the catalyst pretreated in air is not active under the same condition. Pretreatments in both Ar and H 2 O/Ar were found to facilitate the formation of metallic Pd on Pd/Al 2 O 3 catalyst, confirmed by both experiments and calculation based on the function of the equilibrium oxygen pressure and temperature. We further found that the catalyst pretreated in H 2 O/Ar has higher Pd dispersion and more surface OH groups compared to that pretreated in Ar, leading to improved activity in formaldehyde oxidation.
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Xin Huang,Le-Tian Wang,Yan-Fang Song,Fang Ge,Yi Zhang,Xin-Jing Meng,Hong-Hua Ge,Yu-Zeng Zhao
The use of nanofluids as vehicle coolant can significantly improve the heat exchange efficiency, but it is necessary to understand its corrosiveness to metals before use. Corrosion behavior of aluminum alloy in simulated vehicle coolant (SVC), nano Al 2 O 3 coolant (SVC-Al 2 O 3 ), simulated coolant containing sodium dodecyl benzene sulfonate (SVC-SDBS) and nano Al 2 O 3 coolant containing SDBS (SVC-Al 2 O 3 -SDBS) was investigated by electrochemical impedance spectroscopy , polarization curve, weight loss analysis and surface analysis in this paper. The results showed that in the three media of SVC, SVC-SDBS and SVC-Al 2 O 3 -SDBS, the impedance modulus at the frequency of 10 mHz |Z| 0.01 , the charge transfer resistance R ct and the film resistance R f of aluminum alloy electrode increased with the immersion time. Compared with the three media, the aluminum alloy in SVC-Al 2 O 3 medium had the lowest |Z| 0.01 , R ct and R f , and had the highest corrosion current density, implying that Al 2 O 3 nanoparticles promoted the corrosion of aluminum alloy in SVC, and the corrosion products formed on the alloy surface were Al 2 O 3 , Al(OH) 3 , AlOOH, which were loose and not protective. The R f values of aluminum alloy electrode increased significantly with time in the media containing SDBS. The aluminum alloy exhibited the best corrosion resistance in the medium of SVC-SDBS and no obvious loose corrosion products but compact passivation film could be seen on the alloy surface. SDBS exhibited a good corrosion inhibition effect on aluminum alloy, which may be due to the adsorption of SDBS on the metal surface and the fact that SDBS promoted the formation of the passive film by preventing the transformation of alumina film to loose AlOOH layer. In the medium containing both SDBS and Al 2 O 3 nanoparticles, the corrosion inhibition effect of SDBS was weakened. This maybe due to the electrostatic attraction of positively charged Al 2 O 3 nanoparticles and negatively charged SDBS, which reduced the adsorption of SDBS on the metal surface, thereby weakening the protective effect of SDBS on the metal surface.
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高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Huifang Wang,Jun Zhang,Qichong Zhang,Hao Wu,Xiaohong Xu
The p-n heterojunctions with the built-in electric field are often adopted to promote the separation of photoexcited electron-hole pairs and enhance the photoelectrochemical (PEC) performance. However, the interface states often affect the band alignment of ZnO/Cu 2 O heterointerface and cause the decline of PEC performance. In this study, the ultrathin insulating Al 2 O 3 layer was introduced to modify the interface between n-type ZnO nanorod arrays (NRA) and p-type Cu 2 O. Compared to that of ZnO NRA/Cu 2 O, the photocurrent density is significantly improved and onset potential shifts negatively for ZnO NRA-Al 2 O 3 /Cu 2 O. The Al 2 O 3 ultrathin layer is deemed to suppress the photoexcited carriers trapped by the heavy interface defect states via improving the interface quality and block the recombination between electrons in the conduction band of ZnO NRA and holes in the valence band of Cu 2 O. This work broadens the interface modification method of p-n heterojunction and its results are favorable for photovoltaic devices, photodetection and PEC water splitting applications.
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高影响因子
CATALYSIS TODAY
·
2020
·
IF 5.825
Juan Liu,Wen-Ying Li,Jie Feng,Xiang Gao
The improvement of the sulfur tolerance over Pt catalyst is critical for the hydrotreatment of crude oil. Fe was co‒impregnation with Pt on γ-Al 2 O 3 at different calcination temperature. Results revealed that adding Fe significantly facilitated the reduction of Pt oxides for the catalyst calcined at 400 °C. The morphological analysis and CO chemisorption showed Fe improved the dispersion of Pt nanoparticles. The surface chemical state analysis implied the co‒existence of the electron‒deficient Pt and metallic Fe. However, the increase of calcination temperature caused a decreased reducibility of Pt oxides due to strong metal support interaction. A higher dibenzothiophene hydrodesulfurization conversion of 97.7 % with a dominant biphenyl selectivity of 96.7 % were acquired for the catalysts incorporated with Fe. The density functional theory calculations confirmed the alloyed Fe led to the formation of electron‒deficient Pt atoms, and the higher affinity to sulfur made Fe be a favorable additive for noble metal catalyst in the hydrodesulfurization.
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高影响因子
METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
·
2020
·Vol. 52
·期 1
·314-321
·
IF 2.035
Ren Guoxing,Xiao Songwen,Xia Longgong,Liao Caibin,Liu Zhihong
To obtain fundamental information on the dissolution of cobalt into alumina-saturated MnO-SiO 2 -Al 2 O 3 slags in the smelting reduction of spent lithium-ion batteries, the equilibrium distribution of cobalt between Co-Cu alloys and alumina-saturated MnO-SiO 2 -Al 2 O 3 slags was measured at 1573 K and 1623 K under a controlled CO-CO 2 atmosphere. The results show that (i) the solubility of cobalt in the slag increased with increasing concentration of cobalt in the alloy and increasing oxygen partial pressure in the atmosphere at a fixed concentration of cobalt in the alloy, and (ii) the activity coefficient of CoO in the slag increased with increasing cobalt oxide in the slag. The activity coefficient of CoO in the slag, γ CoO, referred to as solid CoO, can be described as a function of the concentration of CoO in slag as follows: γ CoO = 11.2957(wt pct CoO in slag) + 12.0944 (1573 K, (wt pct MnO)/(wt pct SiO 2 )= 0.76–0.83); γ CoO = 2.2286(wt pct CoO in slag) + 4.5232 (1623 K, (wt pct MnO)/(wt pct SiO 2 )= 0.78–0.85).
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高影响因子
FUEL PROCESSING TECHNOLOGY
·
2020
·
IF 4.982
Muhammad Masood Khan,Lijun Jin,Muhammad Mahmood Khan,Yang Li,Hammad Saulat,Yun Zhang,Muhammad Sarfraz,Jialong Zhu,Haoquan Hu
The composite catalysts AC-Ni/MgO-Al 2 O 3 were prepared by the co-precipitation method with activated carbon (AC) and [Ni,Mg,Al]-hydrotalcite as the precursors, and characterized by XRD , TG-DTG, N 2 adsorption, H 2 -TPR and SEM, respectively. The resultant catalysts were examined for CO 2 reforming of methane. The results showed that the introduction of AC into Ni/MgO-Al 2 O 3 catalyst improved the textural properties, especially the surface area and pore volume of mesopores , and decreased the size of metal Ni. Compared with Ni/MgO-Al 2 O 3 , the composite AC-Ni/MgO-Al 2 O 3 exhibited higher catalytic activity , stability and H 2 /CO ratio. But the AC content obviously influenced the catalytic performances. High AC loading resulted in the decline of catalytic activity owing to lower surface area and fewer active Ni content in the catalyst. 10AC-Ni/MgO-Al 2 O 3 with 10% AC displayed the best catalytic activity and stability compared with Ni/MgO-Al 2 O 3 . About 86.2% conversion of CH 4 , 91.3% conversion of CO 2 and above 0.95 ratio of H 2 /CO were achieved over 10AC-Ni/MgO-Al 2 O 3 sample for the reaction time of 5430 min. This work provides a route to improve catalytic performances of Ni-based catalysts in CO 2 reforming of methane.
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