Molecular Catalysis
·
2023
·
IF 4.6
Tiantian Zhang,Jiacheng Xu,Yan Sun,Shiyu Fang,Zuliang Wu,Erhao Gao,Jiali Zhu,Wei Wang,Lianxin Dai,Weihua Liu,Buhe Zhang,Junwei Zhang,Shuiliang Yao,Jing Li
Nano-Au has a good catalytic activity for CO oxidation, but its catalytic mechanism is still not clear. Here, CO oxidation on Au 2 O 3 and its thermal decomposition products were studied using thermogravimetric-mass spectrometry (TG-MS) and operando diffuse reflectance infrared Fourier transform spectroscopy-mass spectrometry (DRIFTS-MS) to explore the key active components of Au catalyst for CO oxidation. The TG-MS results showed that Au 2 O 3 decomposed to AuO at 210 °C and Au at 375 °C and was oxidized to form Au oxide above 375 °C. When Au 2 O 3 decomposed into Au x O y (x>y) above 210 °C, the CO oxidation activity obviously increased. Au atoms in the Au-Au system serve as electron donor and CO adsorption sites. Au atom is oxidized to AuO by the O atom from O 2 decomposition following the Epling-Xu decomposition mechanism. A schematic diagram of the key components of Au 2 O 3 catalysts during CO oxidation was proposed based on TG-MS and operando DRIFTS-MS analysis results.
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
Surfaces and Interfaces
·
2025
·
IF 6.3
Dan Chen,Ming Zhai,Jing Zhang,Liqi Miao,Kan Li,Zhong Wang,Xiaozhi Wang
Gold-based catalysts are renowned for their exceptional low-temperature oxidation activity and have found widespread application in the thermos catalytic oxidation of formaldehyde (HCHO). In this study, an in-situ hydrothermal synthesis method was employed to prepare Au 0.5 Ni x /ATP catalysts. By altering the doping amount of Ni during the synthesis process, the impact of Ni doping on the catalytic reactivity was investigated. Compared to pure gold-based catalysts, the dispersion and sintering resistance of the Au 0.5 Ni x /ATP catalysts were enhanced. The OH - ions present in the alkaline solution provided by TPAOH disrupted the morphology of ATP, leading to a flocculent appearance for the Au 0.5 /ATP catalyst. With varying doping levels of Ni, the rod-like structure of ATP gradually recovered due to the strong interaction between Ni 2+ and OH-. On the Au 0.5 Ni x /ATP catalysts, NiO, being a p-type semiconductor, was prone to electron loss, with the lost electrons being captured by Au 3+ to form Au 0 and stronger Au and Ni interactions. When Ni species were introduced onto the Au/ATP surface, the synergistic effect between Au and Ni resulted in higher catalytic activity, favoring the catalytic oxidation of HCHO. The catalytic efficiency peaked when the Ni doping level reached 20 wt%.
研究领域:
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2019
·Vol. 95
·期 4
·1153-1162
·
IF 2.659
Yihu Ke,Xiaohua Li,Jifan Li,Chun-Ling Liu,Chunli Xu,Wen-Sheng Dong
BACKGROUND Glycerol, which is a coproduct of biodiesel production, has been identified as a key platform compound for producing various valuable chemicals. The selective catalytic oxidation of glycerol to dihydroxyacetone is very attractive. RESULTS A series of Au catalysts supported on metallic oxides, i.e. ZnO, CuO, Al 2 O 3 , Fe 2 O 3 and NiO, were studied for selective catalytic oxidation of glycerol to dihydroxyacetone under base-free conditions. Among the catalysts, Au/CuO showed the best catalytic activity (glycerol conversion of 89% and dihydroxyacetone selectivity of 82.6% at 80 °C under 10 bar of O 2 ), followed by Au/ZnO ≫ Au/NiO > Au/Al 2 O 3 ≈ Au/CuO-SD ≈ Au/Fe 2 O 3 . The catalytic behaviors of these supported Au catalysts varied depending on the Au particle size, Au oxidation state, Au–support interactions and lattice oxygen reducibility. CONCLUSION The main reasons for the high catalytic activity of Au/CuO are as follows. Firstly, the catalyst has small metallic Au particles, which are more active in cleavage of the secondary C H bond in glycerol molecules. Secondly, the interactions between Au and CuO facilitate lattice oxygen reduction, and this increases oxygen mobility, which may promote regeneration of Au–support perimeter active sites by gaseous oxygen. © 2019 Society of Chemical Industry
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
Catalysts
·
2018
·Vol. 8
·期 4
·147
·
IF 3.465
Xiaoyu Chang,Junjiao Yang,Dandan Han,Bing Zhang,Xu Xiang,Jing He
Light-driven production of hydrogen peroxide (H2O2) is a green and sustainable way to achieve solar-to-chemical energy conversion. During such a conversion, both the high activity and the stability of catalysts were critical. We prepared an Au-supported C3N4catalyst—i.e., Au/C3N4-500(N2)—by strongly anchoring Au nanoparticles (~5 nm) onto a C3N4matrix—which simultaneously enhanced the activity towards the photosynthesis of H2O2and the stability when it was reused. The yield of H2O2reached 1320 μmol L−1on Au/C3N4-500(N2) after 4 h of light irradiation in an acidic solution (pH 3), which was higher than that (1067 μmol L−1) of the control sample Au/C3N4-500(Air) and 2.3 times higher than that of the pristine C3N4. Particularly, the catalyst Au/C3N4-500(N2) retained a much higher stability. The yield of H2O2had a marginal decrease on the spent catalyst—i.e., 98% yield was kept. In comparison, only 70% yield was obtained from the spent control catalyst. The robust anchoring of Au onto C3N4improved their interaction, which remarkably decreased the Au leaching when it was used and avoided the aggregation and aging of Au particles. Minimal Au leaching was detected on the spent catalyst. The kinetic analyses indicated that the highest formation rate of H2O2was achieved on the Au/C3N4-500(N2) catalyst. The decomposition tests and kinetic behaviors of H2O2were also carried out. These findings suggested that the formation rate of H2O2could be a determining factor for efficient production of H2O2.Keywords:hydrogen peroxide;Au catalyst;photosynthesis;carbon nitride
研究领域:
化学
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2023
·Vol. 13
·期 5
·864
·
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
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2020
·Vol. 22
·期 8
·2588-2597
·
IF 9.48
Xintong Meng,Zengyong Li,Di Li,Yiming Huang,Jiaojiao Ma,Chuanfu Liu,Xinwen Peng
Catalytic and selective oxidation of monosaccharides into value-added sugar acids is highly desirable from both scientific and industrial perspectives. Here, we report a hierarchical porous carbon (NC-3) supported gold catalyst (Au/NC-3) and its application in the base-free aerobic oxidation of D-glucose and D-xylose into value-added sugar acids under mild conditions (100 °C). The catalyst exhibited excellent catalytic performance with the yields of D-gluconic acid and D-xylonic acid reaching 97.62% and 98.76%, respectively. We studied the effect of the ball-milling process on the hierarchical porous preparation, which is critical to the formation of the fibrous structure during the pyrosis process. This specific structure provides active sites for Au adsorption. DFT calculation revealed that the Au NPs prefer to anchor on pyridinic N sites; meanwhile, the initial reactants and essential intermediates are found to be well stabilized by Au/NC-3. Moreover, upon recycling, gold was stable toward the recovery procedure. In this work, we provide a green method for an improved generally selective oxidation of D-glucose and D-xylose using Au/NC-3 as an efficient heterogeneous catalyst.
研究领域:
化学
·
催化科学
✓ 已验证
DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2013
·Vol. 109
·期 2
·551-562
·
IF 1.104
Cui Wenjing,Zhu Huaiyong,Jia Meilin,Ao Wulan,Zhang Yulin,Zhaorigetu Bao
Imines were synthesized from benzyl alcohol and amines by using catalysts of gold nanoparticles supported on ZrO 2 (Au/ZrO 2 ). The effects of reaction time, temperature, gold loadings and base were investigated. High yields were achieved under moderate conditions (60 °C) in the presence of KOCH 3 . For instance, the yield of N -benzylidenebenzylamine produced from benzyl alcohol and benzylamine on 3 wt% Au/ZrO 2 is 87 %. The synthesis of imine involves two reaction steps: selective oxidation of benzyl alcohol to benzaldehyde and the coupling reaction of amines with benzaldehyde. In the first step, the base promotes the selective oxidation. The reactions of benzyl alcohol with three different amines, aniline, n -butylamine and benzylamine, were conducted to produce corresponding imines. The results show that the amine with stronger nucleophilicity has better ability to react with benzaldehyde in the second step, resulting in higher yield of the corresponding imine. We proposed a tentative mechanism for the synthesis process.
研究领域:
催化化学
·
有机合成
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2023
·Vol. 16
·期 8
·3139
·
IF 3.4
Hangwei Jiang,Xiya Chen,Danlan Cui,Kun Lu,Xiao Kong,Xingguang Zhang
Conventional methods to prepare supported metal catalysts are chemical reduction and wet impregnation. This study developed and systematically investigated a novel reduction method based on simultaneous Ti3AlC2fluorine-free etching and metal deposition to prepare gold catalysts. The new series of Aupre/Ti3AlxC2Ty catalysts were characterized by XRD, XPS, TEM, and SEM and were tested in the selective oxidation of representative aromatic alcohols to aldehydes. The catalytic results demonstrate the effectiveness of the preparation method and better catalytic performances of Aupre/Ti3AlxC2Ty, compared with those of catalysts prepared by traditional methods. Moreover, this work presents a comprehensive study on the influence of calcination in air, H2, and Ar, and we found that the catalyst of Aupre/Ti3AlxC2Ty-Air600 obtained by calcination in air at 600 °C performed the best, owing to the synergistic effect between tiny surface TiO2species and Au NPs. The tests of reusability and hot filtration confirmed the catalyst stability.Keywords:Ti3AlC2MAX;gold catalysts;novel reduction method;oxidation of aromatic alcohols
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2021
·Vol. 22
·期 16
·8668
·
IF 5.924
Jie Li,Shiyi Wang,Huayin Li,Yuan Tan,Yunjie Ding
The synthesis of ester compounds is one of the most important chemical processes. In this work, Zn-Mg-Al mixed oxides with different Zn2+/Mg2+molar ratios were prepared via co-precipitation method and supported gold nanoclusters to study the direct oxidative esterification of aldehyde and alcohol in the presence of molecular oxygen. Various characterization techniques such as N2-physical adsorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and CO2temperature programmed desorption (TPD) were utilized to analyze the structural and electronic properties. Based on the results, the presence of small amounts of Zn2+ions (~5 wt.%) provoked a remarkable modification of the binary Mg-Al system, which enhanced the interaction between gold with the support and reduced the particle size of gold. For oxidative esterification reaction, the Au25/Zn0.05MgAl-400 catalyst showed the best performance, with the highest turnover frequency (TOF) of 1933 h−1. The active center was believed to be located at the interface between metallic gold with the support, where basic sites contribute a lot to transformation of the substrate.Keywords:gold catalyst;cluster;hydrotalcite;oxidative esterification;methyl isobutyrate
研究领域:
化学工程
·
催化材料
✓ 已验证
DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Xiaoting Deng,Shaofeng Yin,Xiaobo Wu,Min Sun,Zhiyong Xie,Qizhong Huang
To enhance the activity and durability of platinum (Pt) or platinum-based catalysts for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs), fabrication of low-cost platinum catalysts with durable structure is necessary. Here, a series of one-dimensional (1D) platinum-gold/titanium dioxide nanowires (PtAu/TiO 2 NWs) catalysts with different Pt/Au/Ti ratios were synthesized by electrospinning, and the microstructure as well as its electrochemical properties for ORR were investigated. The results illustrate that PtAu/TiO 2 NWs indicate a parabolic-type ORR performance as a function of compositions . The optimized Pt 1 Au 1 /(TiO 2 ) 1 NWs exhibited 4.19 times in mass activity and 2.82 times in SA when compared with commercial Pt on carbon catalyst (20% Pt/C). In addition, the stability test shows that the ECSA of Pt 1 Au 1/ (TiO 2 ) 1 NWs present almost 20% decrease, while the 20%Pt/C drops more than 40% at the same condition. The extraordinary activity of Pt 1 Au 1/ (TiO 2 ) 1 NWs could be attributed to the synergistic effect of TiO 2 and the durability attributed to Au and C skin. The nanowires with larger specific area show that the Pt electronic structure can be changed by the neighbouring TiO 2 , further decreasing the d-band gap to enhance catalytic activity.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
·
2023
·Vol. 26
·期 8
·e202201497
·
IF 2.8
Wenqian Du,Rongjie Yang,Jiawen Wu,Zhonghua Xia
Graphical Two flexible methods for synthesizing benzofuran-3(2H)-ones are developed, with easily available starting materials, good chemoselectivity, and very mild conditions. One protocol for benzofuranone is a gold-catalyzed cycloisomerization of o -alkynyl phenol with alcohol or acid. Another metal-free synthesis of benzofuranone is the treatment of benzofuran with alcohol, acid, or H 2 O. Benzofuranones are attractive synthetic targets in medicinal and natural products. The cycloisomerization of o -alkynyl phenol to benzofuran-3(2H)-one is reported here using gold(I) and Selectfluor. This benzofuranone can also be obtained from benzofuran without a gold catalyst. This study presents two appealing synthetic methods for benzofuran-3(2H)-ones that use readily available starting materials, have high chemoselectivity and operate under very mild conditions.
研究领域:
有机化学
·
药物化学
·
合成化学
✓ 已验证
DOI
高影响因子
CATALYSIS LETTERS
·
2016
·Vol. 147
·期 1
·102-109
·
IF 2.294
Zhang Yifei,Zhang Shaohua,Pan Xiaoli,Bao Ming,Huang Jiahui,Shen Wenjie
Abstract Uniform Au particles with a mean size of 1.9 nm were initially synthesized with polyvinyl alcohol (PVA) as protecting agent, and then deposited on MgO, Al 2 O 3 , TiO 2 , Fe 2 O 3 , Co 3 O 4 , ZnO and In 2 O 3 . After calcinations at 300 °C in air to remove PVA, Au particles were highly dispersed and immobilized on all the supports, displaying narrow diameter distributions and almost identical mean sizes of 2.5–3.2 nm. The Au-oxides catalysts were further used to catalyze selective hydrogenation of cinnamaldehyde (CAL) to cinnamyl alcohol (COL). It was found that the selectivity of COL was tightly related to the acidity/basicity of the Au/oxides catalysts. The catalyst with only acidic sites such as the Au/Al 2 O 3 catalyst gave very low selectivity of COL of 15%. The catalysts with only basic sites such as Au/MgO catalyst displayed medium selectivity of COL of 52%. Interesting, the Au catalysts with both acidic and basic sites such as the Au/In 2 O 3 and Au/ZnO catalyts exhibited the highest selectivity of COL of around 86%. The synergistic cooperation of acidic sites and basic sites should be responsible for preferential adsorption and activation of the C=O group than C=C group in CAL, and then preferential hydrogenation of C=O to COL. Graphical Abstract
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
危险品化学品经营许可证（带存储）