GREEN CHEMISTRY
·
2014
·Vol. 17
·期 1
·453-459
·
IF 6.852
Muge Niu,Yucui Hou,Shuhang Ren,Weize Wu,Kenneth N. Marsh
Formic acid (FA) is an important material widely used in the chemical industry and in processes involved in energy storage and transformation. In this work, production of FA from wheat straw, an abundant lignocellulosic biomass, in NaVO3–H2SO4 aqueous solution with molecular oxygen (O2) was studied. The conversion showed high efficiencies: 47% (based on carbon, 75.2% based on mass) of FA and 7.3% (based on carbon, 7.6% based on mass) of acetic acid were obtained. The products mainly come from polysaccharides (hemicellulose and cellulose) in wheat straw. Acetic acid is derived from the acetyl groups in (1) the hemicellulose structure or (2) the deep hydrolysis product, levulinic acid. The removal of each lignocellulosic component in wheat straw follows the order: hemicellulose, lignin and cellulose. The catalytic system shows good reusability, and multiple feedings led to a high concentration of FA, which is beneficial to reduce FA–water separation cost.
研究领域:
生物化学
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2020
·Vol. 35
·期 1
·e6073
·
IF 3.14
Jianyu Dong,Xiuling Chen,Fangyan Ji,Lixin Liu,Lebin Su,Min Mo,Jian-Sheng Tang,Yongbo Zhou
A simple and direct aerobic oxidative esterification reaction of arylacetonitriles with alcohols/phenols is achieved in the presence of a copper salt and molecular oxygen, which produces a broad range of aryl carboxylic acid esters in good to high yields. Copper salt plays multiple roles in the transformation, which allows the oxygenation of C H bond, cleavage of inert C C bond, and formation of C O bond in one pot without the assistance of any of the acids, bases, ligands, and so on. The reaction provides a simple, direct, and efficient protocol towards functionalized esters, especially aryl benzoates, from readily available starting materials.
研究领域:
有机化学
·
合成化学
✓ 已验证
DOI
高影响因子
GREEN CHEMISTRY
·
2023
·
IF 9.8
Shihao Su,Guojun Lv,Xuyang Zou,Jiangzhang Wang,Chaoyi Zhou,Yan Chen,Jialing Shen,Yangbin Shen,Zhongmin Liu
In the cyclic alkene epoxidation reactions using molecular oxygen as oxidant, aldehyde is generally added as co-oxidant to assist transition metal catalyst to activate the oxygen molecule, oxidizing cyclic alkene and producing the corresponding epoxide; however, the added aldehyde would be converted into byproduct carboxylic acid. Herein, we report the room-temperature tandem conversion of cyclic alkenes into 1,2-diols through the application of byproduct carboxylic acid as a catalyst for epoxide hydration reaction, realizing effective utilization of the byproduct and saving energy consumption. Four kinds of nanosized MnO2 specimens, including α-, β-, δ-, and γ-MnO2, were hydrothermally synthesized and applied as heterogeneous catalysts for the room-temperature tandem conversion of cyclohexene into 1,2-cyclohexanediol using molecular oxygen as oxidant and isobutyraldehyde as co-oxidant. The characterization results demonstrated that the obtained β-MnO2 sample had the maximum Mn4+/Mn3+ ratio of 1.42 and the minimum Oads/OLatt ratio of 0.34, consistent with its least oxygen vacancies evidenced by EPR measurement. Accordingly, the β-MnO2 sample revealed the quickest alkene epoxidation reaction rate and could achieve a 99.2% cyclohexene conversion within 1 h, and meanwhile, a 73.6% 1,2-cycloheanediol yield could be attained within 24 h. A plausible mechanism for the tandem conversion of cyclohexene into 1,2-cyclohexanediol over the β-MnO2 heterogeneous catalyst was proposed and further verified by quenching experiments and DFT calculations. Furthermore, the synthesized β-MnO2 catalyst sample could be reused more than ten times, and meanwhile, the tandem conversion way could be expanded to most of the cyclic alkene substrates, which demonstrated that the β-MnO2 catalyst was an active and stable heterogeneous catalyst for tandem conversion of cyclic alkenes into 1,2-diols.
研究领域:
催化化学
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环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Chuanjian Su,Chaolin Li,Ruhong Li,Wenhui Wang
Piezocatalytic molecular oxygen activation has been regarded as a promising and low energy-cost strategy for environment remediation, yet the piezocatalytic activity is still far from satisfactory and little is known on its activation mechanism, which greatly hinders its further development. Herein, the piezocatalyst Bi 2 Fe 4 O 9 nanosheets (BFO NSs) are synthesized via a facile hydrothermal method, which exhibit excellent piezocatalytic performance for sulfamethoxazole degradation. O 2 ∙ - generated via the molecular oxygen reduction reaction by piezo-electrons and the piezo-holes were confirmed as major active species for organic pollutants degradation. Further theoretical calculations and XPS analyses confirm the Fe 2+ sites as active centers activate molecular oxygen into O 2 ∙ - via donating the electrons to molecular oxygen and the piezo-electrons reduce Fe 3+ to Fe 2+ . This work provides atomic-scale insights into the active sites of piezocatalytic molecular oxygen activation, which can inspire the development of more efficient piezocatalysts for environment application.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 81
·51142-51150
·
IF 3.108
Ruilian Li,Jian Zhao,Fengxia Yang,Yingchao Zhang,Daniele Ramella,Yu Peng,Yi Luan
A novel magnetic Fe3O4@P4VP(poly(4-vinylpyridine))@FeCl3 core–shell structure was successfully synthesized. Its Fe3O4@P4VP core was initially prepared via polymerization of 4-vinyl pyridine on the surface of Fe3O4 microspheres. The successful introduction of the FeCl3 moiety as a catalytic active site was achieved through coordination interaction between P4VP and FeCl3. The obtained Fe3O4@P4VP@FeCl3 catalyst was applied in the selective oxidation of alcohols using molecular oxygen as the oxidant. It was shown that a variety of alcohol substrates is tolerated under optimized reaction conditions. Additionally, benzylic oxidation of hydrocarbon compounds was also evaluated using Fe3O4@P4VP@FeCl3 as the catalyst and tBuOOH as the oxidant, achieving high yields and very good selectivities. The heterogeneity of the Fe3O4@P4VP@FeCl3 core–shell catalyst was tested and the initial activity was maintained after five reuses.
研究领域:
化学
·
催化科学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2017
·
IF 9.446
Shao-jia Liu,Fa-tang Li,Yi-lei Li,Ying-juan Hao,Xiao-jing Wang,Bo Li,Rui-hong Liu
The mismatches of lattices and energy bands in heterojunction are the dominant factors restricting the generation efficiency of reactive oxygen species (ROS) that are powerful tools for water purification and anti-bacteria. In this paper, the mediated lattice matching role of amorphous Al 2 O 3 is presented for constructing the ternary g-C 3 N 4 /Al 2 O 3 /ZnO heterojunctions, which exhibit higher molecular oxygen activation performance than binary g-C 3 N 4 /ZnO and g-C 3 N 4 /Al 2 O 3 heterojunctions. The oxygen activation ability and the ROS generation were testified by the electron paramagnetic resonance (EPR) measurement, transformation of nitroblue tetrazolium (NBT) and degradation of methylene blue (MB). The ROS include superoxide anion radical ( O 2 − ) and consequent product of hydroxyl radical ( OH). The superior oxygen activation performance of the ternary heterojunctions can be attributed to the lattices matching of the mediated amorphous Al 2 O 3 and the resultant efficient cascade electron transfer.
研究领域:
材料科学
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环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2023
·
IF 7.3
Lei Wang,Yonggang Sun,Yulong Ma,Min Xu,Juan Zhang,Yingbo Zhu,Jie Ding,Li Zhu,Jing Ma,Wenxin Ji,Liqiong Wang,Yuanyuan Li
Dual activation of molecular and lattice oxygen is an important step in the catalytic oxidation of volatile organic compounds. Herein, CeO 2 was derived from MOF as an electron donor support to develop a co-catalyst with Pt-Pd alloy nanoparticles (Pt-Pd/CeO 2 ). The Prepared Pt-Pd/CeO 2 exhibits excellent catalytic activity towards toluene oxidation, showing a turnover frequency (TOF 0.26 s −1 ) higher than those of Pt/CeO 2 (0.05 s −1 ) and Pd/CeO 2 (0.02 s −1 ). Several in situ experimental techniques and density functional theory calculations have revealed that the introduction of Pd valence electrons can intensify the electronic metal-support interactions (EMSIs) effects of Pt-Pd/CeO 2 catalysts, which can weaken the Ce-O bond, thereby promoting the production and circulation of lattice oxygen and oxygen vacancies, and modulating the d -band centre to enhance the adsorption and activation of reactants. This study presents a comprehensive investigation of toluene oxidation on alloy-supported catalysts, providing practical guidance for designing reliable catalysts suitable for industrial applications.
研究领域:
催化化学
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环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Zhiyang Zhang,Mi Hu,Qingfeng Gui,Jing Gu,Wenlong Xu,Qingbo Xiao,Wei Huang
Adipic acid is a valuable chemical used to product Nylon-66, and one of the greenest ways to synthesize it is catalyzing the oxidation of cyclohexane by molecular oxygen in the absence of any other chemicals. However, it is challenging to convert cyclohexane effectively with high selectivity to adipic acid using the available catalysts. In response to the dilemma of achieving satisfactory conversion and selectivity at the same time, a remarkable Au@NaX catalyst is proposed using an improved in-situ crystallization method that exhibits Au clusters surrounded by X-zeolite channels. A 29.5% conversion of cyclohexane and an 85.6% selectivity to adipic acid can be obtained in a one-pot oxidation of cyclohexane at 140 °C, 20 bar O 2 , far exceeding most published results. Since determined by detailed characterizations and DFT calculations, the effective dynamic collaboration between Au clusters and zeolite inner micro-environment is the decisive role for superior catalytic performance. Specifically, the surrounding zeolite channel encourages the adsorption and activation of cyclohexane over the confined Au clusters, resulting in an unprecedented activity. The continuous oxidation of cyclohexanol and cyclohexanone to adipic acid is also vulnerable on the enclosed Au clusters, and the subsequent adipic acid can be further stabilized as a result of the strong interaction of –COOH with Na ± in zeolite channels surrounding enclosed Au clusters. It prevents AA from poisoning active sites and generates a higher selectivity for the desired adipic acid. Our study highlighted the critical significance of the dynamic interaction between metal clusters and the zeolite channel microenvironment. It would shed light on the further high-performance catalysts designs for selective oxidation.
研究领域:
催化化学
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Xin Hu,Huiping Zhao,Ying Liang,Rong Chen
Solar-driven molecular oxygen activation is of great importance for reactive oxygen species (ROS) production in environmental remediation. In this work, a convenient bromine doping strategy was developed to mediate the energy level of Bi 2 O 2 CO 3 for molecular oxygen activation. The band structure and DFT calculation demonstrate that the Fermi level of Bi 2 O 2 CO 3 elevates after bromine doping, which promotes the molecular oxygen activation and ROS production. The Br-doped Bi 2 O 2 CO 3 exhibits remarkably enhanced photocatalytic ability and could degrade 95% of the ciprofloxacin within 30 min. Moreover, HPLC-MS analysis elucidates that the pyrrolidone ring degradation process is the dominate pathway in ciprofloxacin degradation over Br-doped Bi 2 O 2 CO 3 , resulting in the decrease of antimicrobial activity of the degradation products and the risk of drug-resistance. This work not only provides a molecular oxygen activation strategy via energy level mediation, but also helps us to further understand the relationship between the elemental doping and molecular oxygen activation.
研究领域:
环境科学
·
材料科学
·
化学
✓ 已验证
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2021
·
IF 8.198
Jianyi Lei,Jiajun Dai,Kok Bing Tan,Jiale Huang,Guowu Zhan,Qingbiao Li
Direct epoxidation of propylene to propylene oxide (PO) with molecular oxygen as the most atomically economical route remains challenging due to the low PO yield. In this study, CuO supported on perovskites (LaCoO3) modified with NaCl was found to be active for direct epoxidation of propylene with oxygen. LaCoxCu1–xO3– modified with alkali metal salts were further fabricated to improve catalytic performance with the assistance of citric acid. Among the investigated catalysts, LaCo0.8Cu0.2O3−δ exhibited the best catalytic performance, with a PO formation rate of 60.4 gPO·kgcat−1·h−1 (PO selectivity of 10.2% and propylene conversion of 12.0%) at a lower temperature (250 °C). The characterization results indicate that Cu-doped LaCoO3 catalysts with enhanced oxygen vacancies and abundant electrophilic oxygen species are crucial to selectively attack on C═C bond instead of C–H bond. Besides, LaCoxCu1–xO3−δ catalysts demonstrated higher propylene conversion and more stable catalytic performance. This work exemplifies the direct propylene epoxidation with molecular oxygen employing perovskite materials.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL POLLUTION
·
2024
·
IF 7.6
Xiaoman Yu,Menglin Liu,Haiming Xu,Jian Xu,Jiarui Yi
Enhancing adsorption ability of photocatalyst by vacancy is a fascinating strategy. Thus, Bi 2 WO 6 /BiOCl with millefeuille-like was successfully prepared via multi-pots method. Experimental results discern that BOW-10 can degraded 75.19% doxycycline hydrochloride (DOC, 20 mg/L) in 1 h, which is 1.3 and 3.5-fold larger than Bi 2 WO 6 and BiOCl, respectively. The mechanism revealed that OVs (oxygen vacancies) not only promote the adsorption of DOC and O 2 but also augment the activation ability of molecular oxygen. Therefore, photo-induced electrons can rapidly transfer from BiOCl to Bi 2 WO 6 via carrier transport channels formed by interface oxygen vacancies (IOVs) under interfacial electric field (IEF) to reduce the adsorbed O 2 . Finally, DOC was eliminated by O 2 ˙ - and h + . Moreover, the relationship of surface areas, OVs concentration and the separation efficiency of photo-generated carriers was constructed. Meanwhile, the degradation paths of DOC and the toxicity of the intermediates were comprehensively investigated through DFT theoretical calculation. This research provides an innovation approach to regulate the capability of pollution adsorption and molecular oxygen activation by vacancy engineering and heterostructure engineering.
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
Nature Catalysis
·
2022
·Vol. 5
·期 1
·45-54
·
IF 40.706
Qi Guodong,Davies Thomas E.,Nasrallah Ali,Sainna Mala A.,Howe Alexander G. R.,Lewis Richard J.,Quesne Matthew,Catlow C. Richard A.,Willock David J.,He Qian,Bethell Donald,Howard Mark J.,Murrer Barry A.,Harrison Brian,Kiely Christopher J.,Zhao Xingling,Deng Feng,Xu Jun,Hutchings Graham J.
The oxidation of methane, the main component of natural gas, to selectively form oxygenated chemical feedstocks using molecular oxygen has been a long-standing grand challenge in catalysis. Here, using gold nanoparticles supported on the zeolite ZSM-5, we introduce a method to oxidize methane to methanol and acetic acid in water at temperatures between 120 and 240 °C using molecular oxygen in the absence of any added coreductant. Electron microscopy reveals that the catalyst does not contain gold atoms or clusters, but rather gold nanoparticles are the active component, while a mechanism involving surface adsorbed species is proposed in which methanol and acetic acid are formed via parallel pathways.
研究领域:
催化化学
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材料科学
·
环境科学
✓ 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）