Catalysts
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2023
·Vol. 13
·期 5
·864
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IF 3.9
Xiya Chen,Hangwei Jiang,Danlan Cui,Kun Lu,Xiao Kong,Junmeng Cai,Shirui Yu,Xingguang Zhang
In organic synthesis, it is important to control the selectivity target product with high purity and reduce the cost of energy and equipment for separation. This study investigated supported gold catalysts on biochar-modified titanate-based nanofibers in order to regulate the catalytic performances by biochar content and surface properties. The catalysts were characterized by SEM, TEM, XRD, XPS, ICP-OES, UV-Vis to confirm their morphology, particle size distribution of Au NPs, crystal structures, oxidation state of Au and other key elements, real Au loading, and optical properties. In the test of selective oxidation of benzyl alcohol to benzaldehyde, the biochar modification could improve the selectivity toward benzaldehyde. Moreover, the influence of catalyst calcination conditions, reaction time, reaction atmospheres, reaction temperatures and solvent were systematically investigated. These results are useful for peer researchers in rational catalyst design.Keywords:gold catalysts;selectivity regulation;selective oxidation;benzyl alcohol
研究领域:
催化化学
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材料科学
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DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
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2023
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IF 16.5
Yan-Wen Ye,Yi-Ming Hu,Wan-Bin Zheng,Ai-Ping Jia,Yu Wang,Ji-Qing Lu
ABSTRACT Ir nanoparticles (NPs) were synthesized via a colloidal method using tetradecyltrimethyl ammonium bromide (TTAB) as the ligand, and the supported Ir/BN catalysts were employed for selective hydrogenation of crotonaldehyde (CRAL). It was found that by proper thermal treatments, the TTAB-capped Ir NPs were very active and selective for the reaction. The Ir/BN catalyst calcined at 300 °C with surface TTAB residue gave a quasi-steady state turnover frequency (TOF) for crotyl alcohol (CROL) formation of 0.02 s −1 and a CROL selectivity of 94.4%, while that calcined at 500 °C with clean surface gave a TOF of 0.004 s −1 and a CROL selectivity of 56.2%. The Ir-TTAB interface was essential for the enhanced performance. In-situ IR spectra along with kinetic investigation revealed that TTAB improved CRAL adsorption and strengthened C=O adsorption, which accounted for high activity and selectivity. However, high coverage of TTAB on the Ir surface suppressed the H 2 adsorption and consequently lowered the activity. Thus the findings provided useful information on the design of efficient catalysts for selective hydrogenation.
研究领域:
催化化学
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材料科学
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DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2019
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IF 7.015
Wenguang Wang,Ru Liu,Ming Tan,Haixiang Sun,Q. Jason Niu,Tongwen Xu,Victor Nikonenko,Yang Zhang
The current methods for determination of the membrane specific permselectivity between two competing counter-ions are dependent on various factors, which hinder the comparison of ion selectivity of ion selective membranes . In this work, a new characteristic, “ideal selectivity” is suggested to be used for the evaluation of the specific permselectivity of monovalent selective membranes. Ideal selectivity is determined in a single electrolyte solution containing only one of the competing counterions. We show that this characteristic exhibits a stable value, which is independent from the molar fraction of ions in a solution. Thus, it may be directly used to predict the purity of a salt produced in a dynamic selectrodialysis (SED) process with a monovalent selective membrane. To elaborate this, thin film composite (TFC) cation exchange membranes were prepared with piperazine and trimesoyl chloride by interfacial polymerization. These membranes were compared with a commercial monovalent selective cation exchange membrane CIMS (ASTOM, Japan) in view of their permselectivity (Na + /Mg 2+ ) and the performance in SED. The results show that when the TFC membranes were applied in SED, the purity of Mg 2+ in the product reached 75%, which was higher than in the case of CIMS. Furthermore, ideal selectivity of those TFC and CIMS membranes were calculated and fitted with the experimental Mg 2+ purity. It was found that ideal selectivity linearly correlates with the product final purity. The extrapolation of the fitting line predicts that when ideal selectivity approaches to 2, SED process the purity could theoretically approach to 100% in the same experimental conditions. Therefore, ideal selectivity can be used to predict the separation efficiency and the final product purity of SED process.
研究领域:
化学工程
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材料科学
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环境科学
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DOI
高影响因子
JOURNAL OF CATALYSIS
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2020
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IF 7.888
Huiyue Xin,Wenbo Zhang,Xixi Xiao,Li Chen,Peng Wu,Xiaohong Li
Due to coexistence of two conjugated unsaturated functional groups in cinnamaldehyde (CAL), exploring efficient catalysts with desirable selectivity to highly value-added products is still challengeable for the selective hydrogenation of CAL. Herein, Ni x Fe 1- x Al 2 O 4+ δ spinel composite metal oxides (SCMOs) supported Pt catalysts were developed and proved to be active and selective for the selective hydrogenation of CAL. Moreover, the selectivity switch can be realized just by changing the Ni/(Fe + Ni) molar ratios in Ni x Fe 1- x Al 2 O 4+ δ SCMOs. As a result, the excellent cinnamyl alcohol (COL) selectivity (~92.2%) and hydrocinnamaldehyde (HCAL) selectivity (~80.7%) were achieved on Pt/FeAl 2 O 4+ δ and Pt/NiAl 2 O 4+ δ , respectively. Based on the kinetic investigation of further hydrogenation of semi-hydrogenated product, the reason for the selectivity switch with Pt/Ni x Fe 1- x Al 2 O 4+ δ was revealed. In combination with detailed characterization, the excellent COL selectivity on Pt/FeAl 2 O 4+ δ can be attributed to more Pt(1 1 1) facets and FeO x species which can facilitate the preferential activation of C O bonds; while the high HCAL selectivity on Pt/NiAl 2 O 4+ δ is owing to the fact that there are more low coordinated active sites and two neighbouring Pt sites.
研究领域:
催化化学
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材料科学
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高影响因子
ACS Applied Materials & Interfaces
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2025
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IF 8.2
Changjiang Liu,Hu Zang,Xin Liu,Haiyan Lu,Nan Yu,Baoyou Geng
Copper-based catalysts demonstrate distinctive multicarbon product activity in the CO2 electroreduction reaction (CO2RR); however, their low selectivity presents significant challenges for practical applications. Herein, we have developed a multilevel porous spherical Cu2O structure, wherein the mesopores are enriched with catalytic active sites and effectively stabilize Cu+, while the macropores facilitate the formation of a “gas–liquid–solid” three-phase interface, thereby creating a microenvironment with an increasing water concentration gradient from the interior to the exterior. Potential-driven phase engineering and protonation synergistically optimize the reaction pathway, facilitating a switch between CO and C2H4. At a low current density of 100 mA cm–2, the faradaic efficiency (FE) for CO reaches an impressive 96.97%. When the current density increases to 1000 mA cm–2, FEC2H4 attains 53.05%. Experiments and theoretical calculations indicate that at lower potentials, the pure Cu2O phase diminishes the adsorption of *CO intermediates, while weak protonation inhibits hydrogen evolution reactions, thereby promoting CO production. Conversely, at more negative potentials, the Cu0/Cu+ interface and strong protonation generate locally elevated concentrations of *CO and *COOH intermediates, which enhance C–C coupling and deep hydrogenation, ultimately improving selectivity toward C2+ products. This study provides novel insights into the rational design of copper-based catalysts for customizable CO2 electroreduction products.
研究领域:
材料科学
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电化学
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DOI
PubMed
高影响因子
Precision Chemistry
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2023
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IF 0
Yating Lv,Hai Wang,Huixin Wu,Qingsong Luo,Liang Wang,Feng-Shou Xiao
Selective hydrogenation over earth-abundant metal catalysts is challenging but particularly valuable for practical applications in heterogeneous catalysis. Herein, we demonstrate that the catalytic selectivity of the commercial Raney nickel catalyst can be greatly tuned by modulation of the nickel surface by silica. Using quinoline hydrogenation as a model, we show that the silica-modified Raney nickel catalysts exhibit good activity, excellent selectivity, and long stability, whereas the undesired overhydrogenation reactions are effectively hindered. In contrast, the pristine Raney nickel catalyst shows inferior selectivity for the targeted product. Mechanistic studies confirm a positive role of silica to facilitate the desorption of 1,2,3,4-tetrahydroquinoline from the catalyst surface, thus enhancing the product selectivity.
研究领域:
物理化学
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材料科学
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催化化学
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DOI
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
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2019
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IF 2.705
Qianwen Wang,Bingbing Ma,Shinya Fushinobu,Chunfang Zhang,Lian-Hua Xu
Cytochrome P450 enzymes (P450 or CYP) are some of the most versatile biocatalysts , and offer advantages for oxidizing unreactive C–H bonds in mild conditions. In this study, we identified a novel cytochrome P450 154C2 from Streptomyces avermitilis and characterized its function in 2α-hydroxylation of testosterone with regio- and stereoselectivity . To investigate the efficiency of electron transfer , we conducted biotransformation using two different P450 redox partners—RhFRED (RhF reductase domain) from Rhodococcus sp. and Pdx (putidaredoxin)/Pdr (putidaredoxin reductase) from Pseudomonas putida and revealed that RhFRED was more effective than Pdx/Pdr, especially in vivo . The K m and k cat values for testosterone were estimated to be 0.16 ± 0.05 mM and 0.13 ± 0.02 min −1 , and k cat / K m was 0.81 min −1 mM −1 . We also determined the crystal structure of the substrate-free form of CYP154C2 at 1.5 Å resolution. The structure has a closed conformation, and the substrate binding pocket is narrow, which can explain the strict substrate specificity of the enzyme .
研究领域:
生物化学
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酶学
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药物代谢
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DOI
PubMed
高影响因子
TETRAHEDRON
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2024
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IF 2.1
Nan Wang,Yuanyuan Huang,Mengke Wang,Weichun Huang,You Zi
Herein, a new approach for the synthesis of ( Z )- N -alkenyl-2-pyridones from 2-pyridones and propiolates using phosphine catalysis under mild conditions is reported. This dual Z -diastereoselective and N -selective reaction demonstrates excellent selectivity, yielding sole ( Z )- N -alkenyl-2-pyridones. Furthermore, scale-up studies confirm its practical applicability, with consistent efficiencies observed.
研究领域:
有机化学
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合成化学
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DOI
高影响因子
PROCESS BIOCHEMISTRY
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2024
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IF 3.7
Chuang Li,Xian Zhang,Yuqing Wang,Qingtao Liu,Zhou Wang,Rui Huang,Zhenglian Xue
To enrich ‘epoxide hydrolase (EH) tool cabinet’ for preparing enantiopure epoxides and 1,2-diols, a novel microbial EH, Sf EH2, was identified from Streptomyces fradiae SF-2. Bioinformatics analysis indicated that Sf EH2 has typical structural characteristics of α/β-hydrolase fold superfamily. Its coding gene, sfeh 2, was then codon-optimized and amplified. A recombinant (re) Sf EH2-expressing E. coli BL21(DE3) strain ( E. coli / sfeh 2) was constructed through DNA manipulations. Substrate spectrum assay including fifteen common racemic ( rac -) epoxides by E. coli / sfeh 2 showed that re Sf EH2 displayed the highest and best complementary regioselectivities (regioselectivity coefficients, α R = 89.7% and β S = 91.4%) towards rac - 14a , as well as the highest enantioselectivity (enantiomeric ratio, E = 15.3) in S -type towards rac - 15a . Molecular docking simulation revealed that Sf EH2 preferentially attacked C α of ( R )- 14a and C β of ( S )- 14a geometrically. In kinetic parameter analysis, the K m R (5.74 mM) of purified re Sf EH2 for ( R )- 15a was 1.76-fold lower than K m S (10.09 mM) for ( S )- 15a . At last, using 50 mg dry cell weight/mL E. coli / sfeh 2, the scale-up enantioconvergent hydrolysis of 100 mM rac - 14a at 30 °C for 6.0 h afforded ( S )- 14b with 80.9% ee p and 90.1% yield, while the kinetic resolution of 150 mM rac - 15a retained ( S )- 15a with >99.0% ee s and 42.2% yield.
研究领域:
生物化学
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微生物学
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酶工程
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DOI
高影响因子
ACS Omega
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2025
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IF 4.3
Tianfu Wu,Wei Song,Jing Wu,Jian Wen,Wanqing Wei,Liming Liu
Chiral amino alcohols are vital in many biologically active molecules and natural products and are crucial building blocks for the pharmaceutical industry. However, the chemosynthesis of chiral amino alcohols, particularly bichiral amino alcohols, faces challenges related to chemoselectivity and enantioselectivity. Here, a dual-enzyme cascade pathway for the synthesis of bichiral amino alcohols through difunctionalization, exhibiting both high chemo- and stereoselectivity, was proposed for the first time. Among them, NADPH-dependent meso-diaminopyrimidate dehydrogenase from Proteus vulgaris (PvDAPDH) exhibited (R)-selective reductive amination activity, converting ketones into chiral amines; natural glucose dehydrogenase from Bacillus megaterium (BmGDH) not only facilitated NADPH regeneration but also catalyzed the reductive hydroxylation of ketones to chiral alcohols. Second, the rational design of the rate-limiting enzyme PvDAPDH generated the mutant M4 with increased specific activity and catalytic efficiency (kcat/Km) for 16a up to 3.2- and 10.3-fold, respectively, compared to the wild type. Additionally, the yield of mutant M4 for 1a–16a increased by 1.1- to 37-fold compared to the wild type. Finally, two high-value bichiral amino alcohols (14b and 16b) were asymmetrically synthesized from the corresponding bietone via a one-pot dual-enzyme cascade, exhibiting excellent stereoselectivity (dr ≥ 98:2). These findings provide a potential biosynthetic pathway for the green synthesis of bichiral amino alcohols and complement existing synthetic methods.
研究领域:
生物化学
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合成生物学
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制药工程
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DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2024
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IF 20.2
Hongchun Sun,Cui Dong,Chao Feng,Hui Wang,Zhenping Qu
Co 3 O 4 catalysts possess high activity in selective catalytic oxidation of NH 3 (NH 3 -SCO), but the low N 2 selectivity hinders their potential application. To enhance N 2 selectivity, the chemical bonded Nb-O-Co catalyst by the deposition of Nb species onto Co 3 O 4 (Nb/Co 3 O 4 -0.03) is constructed. It shows 100 % NH 3 conversion and 82 % N 2 selectivity at 180°C, and the N 2 selectivity is 2.2-fold higher than that of Co 3 O 4 (38 %). The failure of enhancement in N 2 selectivity for physically mixed Co 3 O 4 and NbO x (NbO x |Co 3 O 4 -0.03) further indicates the crucial role of chemical bonded Nb-O-Co in enhancing N 2 selectivity. In situ diffuse reflectance infrared Fourier transform spectra and NH 3 temperature-programmed desorption results show the formation of new NH 3 adsorption sites. Importantly, intermediates NO - stabled on Nb/Co 3 O 4 -0.03 tends to react with -NH 2 to produce N 2 through internal selective catalytic reduction (iSCR). This work offers insights into enhancing the N 2 selectivity in NH 3 -SCO and advances understanding of iSCR mechanism.
研究领域:
化学工程
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环境科学
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DOI
高影响因子
INORGANIC CHEMISTRY
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2025
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IF 4.7
Chao Yang,Hao Chen,Yuankai Li,Zhelin Su,Yeshuang Wang,Xufei Liu,Huiling Fan
The low sulfur selectivity of Fe-based H2S-selective catalytic oxidation catalysts is still a problem, especially at a high O2 content. This is alleviated here through anchoring FeOx nanoclusters on UiO-66 via the formation of Fe–O–Zr bonds. The introduced FeOx species exist in the form of FeIII and FeII. Therein the FeIII–O species are the predominant active sites for H2S-oxidation. The formed Fe–O–Zr bonds strengthen the redox cycle of FeIII/FeII through promoting electron transfer from Fe to Zr. The FeII–O species can activate molecular oxygen to oxidize H2S into elemental S, which accelerates the formation rate of atomic S, hindering its further oxidation into SO2. The combination of these factors empowers the catalysts, enabling 100% H2S conversion and 98.2% sulfur yield. The catalyst also has satisfactory stability with the sulfur selectivity only decreasing from 98.2% to 91.3% after the reaction going on 50 h. The decreased sulfur selectivity might be caused by the deterioration of pores and the deposition of elemental S on the surface. The former hinders the diffusion of sulfur oligomers timely from pores to the gas phase, while the latter is suspected to capture electrons to promote its further reaction with molecular oxygen.
研究领域:
化学工程
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材料科学
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产品关联
DOI
PubMed
高影响因子
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