INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Huaichang Wang,Xiaobo Wang,Mengran Yu,Jianing Li,Juming Liu
As a classical photocatalyst, nano-TiO2 has been widely investigated globally. However, achieving its photocatalytic activity within the spectral range of 400 to 740 nm through a facile approach remains a challenge. Herein, carboxylated carbon species sensitized nano-TiO2 was successfully synthesized by a low-temperature (300 °C) carbonization method using ethanol as carbon source and modifier and commercially available nano-TiO2 as titanium source. The obtained sensitized TiO2 nanoparticles exhibited excellent full visible-light-driven photocatalytic degradation performance. The synthesized TiO2 samples were comprehensively analyzed using a range of characterization techniques. The results indicate that the sensitization of carboxylated carbon species endows the nano-TiO2 with full-visible light spectral response properties and facilitates the separation of photogenerated electron–hole pairs, which leads to excellent full visible-light-driven photocatalytic degradation performance. This study presents a novel strategy for broadening the spectral response and facilitating the industrial scale-up of commercially available nano-TiO2.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2020
·
IF 3.687
Huahua Zhao,Huanling Song,Fangyuan Wang,Zhichao Miao,Lingjun Chou
In the present work, a new strategy was developed to fabricate strong basicity on mesoporous zirconia by in-situ preservation of carbon species originated from organic template during the thermal treatment of mesoporous ZrO 2 . The carbon species was maintained on mesoporous zirconia by calcination in N 2 prior to the introduction of base precursor KNO 3 . The decomposition temperature of KNO 3 to strongly basic site K 2 O was significantly reduced from higher than 650℃ to about 400℃ in the presence of carbon species, which fascinatingly converted the endothermic decomposition reaction to exothermic process. More importantly, the tetragonal ZrO 2 support with excellent mesostructure was well stabilized by the carbon species after introduction of K species. Therefore, K 2 O supported on mesoporous tetragonal zirconia (K 2 O/M-ZrO 2 -C) were successfully fabricated. The resultant mesoporous basic material presented good activity in the synthesis of dimethyl carbonate (DMC) and the DMC yield was 60.0 %, apparently higher than that (18.1 %) of the catalyst prepared without preserving carbon species (K 2 O/M-ZrO 2 ). The strong basicity and the uniform mesopores of the catalyst were suggested to be contributed to the high activity. The obtained results will provide some fundamental understanding and guidance for rational catalyst design.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Yangyang Liu,Baojian Chen,Rui Liu,Wenqi Liu,Xinhua Gao,Yisheng Tan,Zhenzhou Zhang,Weifeng Tu
Catalytic utilizing of CO 2 into valuable olefins on Fe-based catalysts is a feasible way to mitigate the pressure of carbon neutrality. Herein, by investigating the effects of support (SiO 2 , Al 2 O 3 , CNT, and ZrO 2 ) on the structure and catalytic performance of iron catalysts, we have found that ZrO 2 supported catalysts are more beneficial to olefin selectivity and chain growth. The optimization catalytic performance of FeNa/ZrO 2 displays C 2 -C 7 olefin selectivity of 68.2% (O/P = 8.0) with a space time yields (111.4 g Kg cat -1 h −1 ) at X CO2 = 32.7%, 320 ⁰C, 2.0 MPa, CO 2 /H 2 /Ar = 1:3:3, and 9000 mL g -1 h −1 . Characterizations show that the support regulates the composition of the iron oxide phase and the iron carbide phase and induces to form the highest content of Fe 5 C 2 on the spent FeNa/ZrO 2 , which is probably caused by the carbon rich surface and lower disorder of carbon species. Besides, the higher intensity of CO 2 and CO adsorption and lower intensity of H 2 adsorption is confirmed on the surface of the FeNa/ZrO 2 catalysts, leading to a higher ratio of C/H on the surface of the spent catalysts and consequently inhibiting the hydrogenation of olefins. Therefore, the O/P is 8 times as many as that on the FeNa/SiO 2 and FeNa/Al 2 O 3 . Understanding the effect of support on CO 2 hydrogenation to olefins over iron-based catalysts would be significant for precisely designing new catalysts.
研究领域:
催化化学
·
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2015
·
IF 7.435
Yu Shao,Changsheng Cao,Shiliang Chen,Miao He,Jialin Fang,Jing Chen,Xiaofang Li,Danzhen Li
Nitrogen-doped and carbon species decorated TiO 2 composites (Cts/TiO 2 ) are prepared by using chitosan as a natural nitrogen and carbon source to combine with TiO 2 by a facile and low-cost method for the first time. Their structures and properties are characterized by X-ray diffraction (XRD), UV–vis diffuse reflectance spectroscopy (DRS), Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), N 2 adsorption–desorption isotherms (BET), and electron spin resonance spectroscopy (ESR). The results show that the visible light absorption range of the composites even can be extended to 650 nm. Photocatalytic degradation of Rhodamine B (RhB) under visible light (420 nm < λ < 800 nm) irradiation is used as a model reaction to evaluate the photocatalytic activity of the composites. When the additive amount of chitosan is 0.25 g, the sample Cts/TiO 2 -25 possesses the highest activity, which is over 4.8 times of N-TiO 2 . The detection of active species during the photocatalytic process shows that superoxide radicals (O 2 − ) play the most important role, then the probable degradation mechanism of the photocatalysts is proposed simultaneously. It is hoped that our work will open a new doorway to use a simple and green method to get high-efficiency TiO 2 -based photocatalysts.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Chongyang Wei,Xiaoxue Han,Shouying Huang,Haoting Liang,Yidan Wang,Ting Li,Yong Wang,Yue Wang,Xinbin Ma
In the Fischer–Tropsch synthesis (FTS) reaction, the intricate reaction conditions are prone to induce phase transitions in iron carbides, which markedly affect catalytic performance. Manipulating and stabilizing the active phase is paramount for ensuring the catalyst efficiency. In this study, we regulated the Fe-Zn interaction to investigate the influence of iron carbides and the characteristics of surface carbon species. The strong interaction significantly enhanced the adsorption and dissociation of CO on the catalyst surface, thereby facilitating the formation of carbon-rich Fe 2(.2) C. Consequently, the FeZn-s catalyst exhibited the highest iron time yield (FTY) of 959 μmol CO ·g Fe - 1 ·s - 1 . But meanwhile, the stronger Fe-Zn interaction also accelerated the carbon deposition rate and elevated the graphitization degree of the surface carbon, expediting the catalyst deactivation. These results provide an insight into the modulation and stabilization of iron carbides by adjusting the interaction between the Fe and supports, which inspires the further development of Fe-based catalysts for FTS applications.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2014
·Vol. 113
·期 2
·605-614
·
IF 0.983
Liu Hong,Yang Guohai
Gas-phase transformation of toluene is carried out on Cs-exchanged NaY zeolite in a fixed-bed tubular reactor and it is observed that toluene can transform through dealkylation, producing benzene and a small amount of hydrogen under the experimental conditions. After a definite activation period, the transformation of toluene can achieve its steady state with the yield of benzene above 25 % for a relatively long continuous time at low space velocity. Combining the results of characterization and catalytic performances, it can be concluded that benzene is the steadiest product except the carbonaceous residues within the CsY zeolite pores. The in situ carbonaceous deposition experiment shows a similar trend of the carbonaceous forming process and the yield of benzene, indicating the important role of carbonaceous species in the formation of benzene, i.e., it is necessary for the accumulation of carbonaceous species in the initial stage of reaction. The discovery in the current work sheds light on new strategies for the transformation of other similar compounds.
研究领域:
催化化学
·
材料化学
·
物理化学
·
能源化学
·
工业催化
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 56
·期 1
·364-379
·
IF 3.553
Huo Hang,Jiang Yanqiu,Wang Zhe,Hu Yanjing,Zhao Tingting,Liu Xing,Xu Xianzhu,Lin Kaifeng
Abstract In this paper, urea group functionalized periodic mesoporous organosilica was utilized as matrix to introduce cobalt precursor into framework. After pyrolysis in nitrogen atmosphere, urea group was decomposed into carbon species and simultaneously the cobalt precursor was reduced to metallic cobalt nanoparticles. The metallic cobalt nanoparticles can be stabilized by coordinating to carbonyl oxygen atoms in carbon species. The supported metallic cobalt exhibited excellent catalytic performance towards 4-nitrophenol hydrogenation reaction. The largest turnover frequency number can reach up to 164.8 h −1 , and the reaction rate constant can be as high as 0.77 min −1 . The influence of pyrolysis temperature on catalytic performance was also investigated. Compared with the results obtained by samples prepared with wet impregnation method or different pyrolysis rate, it can be concluded that the coordination to carbonyl oxygen atom in carbon species plays a crucial role in improving electron transfer between metallic cobalt and carbon species during catalytic procedure. Graphic abstract Metallic cobalt nanoparticles with high dispersion were introduced into urea group functionalized mesoporous silica matrix via pyrolysis in nitrogen atmosphere. The coordination to carbonyl oxygen atom enhances the catalytic performance in 4-nitrophenol hydrogenation.
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
RSC Advances
·
2020
·Vol. 10
·期 70
·43193-43203
·
IF 3.119
Jianing Li,Junzhong Wang,Juming Liu,Yan Li,Huiyan Ma,Jucai Yang,Qiancheng Zhang
Nano-TiO2 is a type of environment-friendly and inexpensive substance that could be used for photocatalytic degradation processes. In this study, the multi-type carbon species doped and modified anatase nano-TiO2 was innovatively synthesized and developed to overcome the deficiency of common nano-TiO2 photocatalysts. The multi-type carbon species were derived from tetrabutyl titanate and ethanol as the internal and external carbon sources, respectively. Meanwhile, diverse characterization methods were applied to investigate the morphology and surface properties of the photocatalyst. Finally, the visible-light photocatalytic degradation activity of the collected samples was evaluated by using methyl orange as a model pollutant. The promotion mechanism of multi-type carbon species in the photocatalytic process was also discussed and reported. The results in this work show that the doping and modification of multi-type carbon species successfully narrows the bandgap of nano-TiO2 to expand the light absorption range, reduces the valence band position to improve the oxidation ability of photogenerated holes, and promotes the separation of photogenerated charge carriers to improve quantum efficiency. In addition, the further modification of the external carbon source can promote the surface adsorption of MO and stabilize the multi-type carbon species on the surface of nano-TiO2.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 75
·70747-70755
·
IF 3.289
Huijie Dong,Mingyu Wei,Jun Li,Jia Fang,Long Gao,Xiaoxia Li,Aihua Xu
A graphitic carbon nitride-containing MCM-41 catalyst (g-C3N4/MCM-41) was prepared through an in situ thermal approach and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, N2 adsorption–desorption and X-ray photoelectron spectroscopy. It was found that Acid Orange 7 (AO7) and other five organic dyes can be completely degraded by the g-C3N4/MCM-41 catalyst within 30 min in the presence of peroxymonosulfate (PMS), while g-C3N4 + PMS and MCM-41 + PMS show nearly no activity. A non-radical pathway accompanied by radical generation in PMS activation and AO7 oxidation is proposed. The oxidized carbon species N–C–O on g-C3N4 with strong electron density plays a key role in the reaction, while the large surface area of the catalyst can also efficiently enhance the accessibility of catalytic active sites. Though the reusability of the g-C3N4/MCM-41 catalyst is not very good as that of metal oxide catalysts, its activity can be recovered by KOH treatment. The study can broaden the application of g-C3N4 in the area of wastewater treatment.
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
Science Advances
·
2023
·Vol. 9
·期 24
·
IF 13.6
Mingrui Wang,Peng Wang,Guanghui Zhang,Zening Cheng,Mengmeng Zhang,Yulong Liu,Rongtan Li,Jie Zhu,Jianyang Wang,Kai Bian,Yi Liu,Fanshu Ding,Thomas P. Senftle,Xiaowa Nie,Qiang Fu,Chunshan Song,Xinwen Guo
The decomposition of cobalt carbide (Co 2 C) to metallic cobalt in CO 2 hydrogenation results in a notable drop in the selectivity of valued C 2+ products, and the stabilization of Co 2 C remains a grand challenge. Here, we report an in situ synthesized K-Co 2 C catalyst, and the selectivity of C 2+ hydrocarbons in CO 2 hydrogenation achieves 67.3% at 300°C, 3.0 MPa. Experimental and theoretical results elucidate that CoO transforms to Co 2 C in the reaction, while the stabilization of Co 2 C is dependent on the reaction atmosphere and the K promoter. During the carburization, the K promoter and H 2 O jointly assist in the formation of surface C * species via the carboxylate intermediate, while the adsorption of C * on CoO is enhanced by the K promoter. The lifetime of the K-Co 2 C is further prolonged from 35 hours to over 200 hours by co-feeding H 2 O. This work provides a fundamental understanding toward the role of H 2 O in Co 2 C chemistry, as well as the potential of extending its application in other reactions.
研究领域:
催化化学
·
化学工程
·
材料科学
·
可持续能源
·
多相催化
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2022
·
IF 3.119
Xiaohui Song,Jinqiu Ma,Lingzong Meng,Tianlong Deng,Yafei Guo,Yong Ma,Dan Li
The solubilities, refractive indices, and pH values in the NaCl–Na2SO4–NaHCO3–H2O system at 323.15 K were determined by the isothermal solubility method. The dry-salt diagram of the system consists of three isothermal solubility curves saturated with two salts, one invariant point, and three crystallization regions of NaCl, Na2SO4, and NaHCO3. Two models were applied to predict the solubilities in the system based on the Pitzer model. Model I assumes that there is only one carbon species HCO3– in the solution. Model II supposes that there are three carbon species corresponding to HCO3–, CO32–, CO2(aq), and OH– in the solution. Both the computed solubilities with the two models were basically consistent with experimental results. The concentrations of HCO3–, CO32–, CO2(aq), and OH– were calculated by model II. The dominant form of carbon species is HCO3–, and the concentrations of CO32– and CO2(aq) in the sodium bicarbonate solution can be neglected. Model II can be used to describe the experimental pH values. The mean activity coefficients of NaCl, Na2SO4, and NaHCO3, osmotic coefficients, and water activities were also calculated with the Pitzer model.
研究领域:
物理化学
·
热力学
·
溶液化学
✓ 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）