The hydrogenation of CO2 to light olefins is a key route for converting waste carbon into value-added chemicals, and FeCx catalysts exhibit high activity and promising application potential. However, FeCx or Fe0 active sites can be oxidized by H2O generated during the reaction, severely compromising the activity and stability of Fe-based catalysts. Herein, FeCx active species confined within F-doped mesoporous carbon were prepared using a F-functionalized carbon source, constructing a H2O-resistant interface to protect FeCx from oxidation. Under the reaction conditions of 320 °C, 3.0 MPa, H2/CO2 = 3, and GHSV = 6000 mL/gcat/h, the 0.8Fe-0.1K@NMC-0.2F catalyst exhibited a CO2 conversion of 47.24% and a light-olefin selectivity of 52.43%. A light-olefin space-time yield of 36.5 mmol/gcat/h was achieved over 100 h at a high GHSV of 24,000 mL/gcat/h, surpassing the performance of most reported catalysts. The structure-performance relationship and stability enhancement mechanism were investigated using various characterization techniques, revealing that F incorporation enhances the graphitization degree and H2O resistance of the carbon layer, regulates the electron distribution, and promotes the formation of unsaturatedly coordinated Fe5C2 active sites. The F-doped graphene interface modulated the electronic structure of FeCx active sites to enhance CO2 adsorption-dissociation while weakening H2 activation, increasing the surface C/H ratio, and promoting the C-C coupling reaction. Furthermore, the F-functionalized graphene layer suppressed the overcarbonization and H2O-induced oxidation of Fe0 species, boosting the catalytic stability. This work provides a new strategy for the design of high-performance and long-lifetime FeCx catalysts for the cost-effective conversion of CO2 to high-value chemicals and new insights into the stability enhancement mechanism of Fe active sites against H2O generated during the hydrogenation reaction.

ZSM-48 shows excellent performance in shape selective catalysis, especially in hydroisomerization reaction. However, adjusting the acidity of ZSM-48 and improving the synergy of acidic and metal sites are still major challenges in the application of ZSM-48 in hydroisomerization reaction. The dispersing Nb species on support can better utilize the active Nb species and regulate support surface acidity. In this paper, we develop a new route to regulate ZSM-48 surface acidity through Nb modified. The different Nb modified ZSM-48 is prepared under mild conditions and is characterized by physico-chemical characterization techniques such as XRD, N2 physisorption, NH3-TPD, SEM, Py-IR. Owing to its unique acidity, Nb-modified Pt/ZSM-48 exhibits better performance on the hexadecane hydroisomerization compared with Pt/ZSM-48. The selectivity of i-C16 can reach 87 wt% over Pt/ 20Nb/ZSM-48. The addition of Nb not only improves i-C16 selectivity but also enhances the stability of the catalyst. Our results provide a facile strategy to adjust the surface acidity of ZSM-48 as solid acids for catalytic applications.

Propylene, as an important chemical basic raw material, is in increasing demand year by year. Au/ZSM-5 as a bifunctional catalyst exhibits excellent catalytic performance and propylene selectivity in low-temperature catalytic cracking to propylene reaction. The smaller Au size (5.8-8.2 nm) is prepared through deposition precipitation, but the characteristics of support will also undergo partial changes at the same time. The support characteristics have been confirmed to have changed through a series of characterizations. The propylene yield could reach 42% at 410 oC when the value of CH/CM is 40. A proposed metal-acid synergistic catalysis mechanism for octane catalytic cracking to produce propylene is elucidated. The higher propylene yield is attributed to the synergy between acid sites and Au species. Our research results provide a reasonable and effective correlation between the metal-acid activity of bifunctional catalysts and catalytic activity in catalytic cracking reactions to produce propylene.

为提高以惰性氧化铝为载体所担载的纳米金催化剂的CO氧化反应活性和稳定性,本研究设计了一种采用沉淀水热法合成的具有层状褶皱似的粗糙表面的氧化铝多孔载体,并以此为载体担载纳米Au粒子且用于CO氧化反应.系列表征结果表明,与直接沉淀法制得的氧化铝相比,沉淀水热法制备的氧化铝载体存在大量的褶皱似的粗糙表面且富含更多的羟基物种,促进了纳米金粒子在载体表面的高度分散,从而提高了其CO氧化反应活性和反应稳定性.

Aromatic amines with high added value are important raw materials for the preparation of dyes, fluorescent brighteners, stabilizers and other fine chemicals, which are of great value in the research of coatings, pharmaceuticals and pesticides.The Ru/TiO 2 catalyst was prepared by impregnation method using the TiO 2 carrier distributed by Shanghai Chemical Reagent Company and prepared by China Institute of Nonferrous Metals Chemistry.They were respectively applied to the hydrogenation of 3-nitrostyrene, and their catalytic activities were compared.The results show that the precious metal ruthenium has relatively ideal catalytic performance when loaded on the TiO 2 carrier prepared by the China Institute of Nonferrous Metals Chemistry.Under the conditions of a pressure of 0.5 MPa, reaction temperature of 40 ℃,and reaction time of 3 h, the conversion rate of 3-nitrostyrene was 95.6%,and the selectivity of 3-vinylaniline was 90.1%.The catalysts were analyzed by X-ray diffraction（XRD）,Fourier transforms infrared spectroscopy（FT-IR）,physical adsorption（BET）,chemical adsorption（H 2 -TPR）,and other characterization methods, and the metal-support relationship was discussed.The interactions between the metal-support and the crystal structure of the TiO 2 support on the catalytic reaction were also discussed.

由于贵金属铑催化剂的成本、需求日益增加,提高铑催化剂在氢甲酰化反应中的催化性能显得尤为重要.且铑催化剂在氢甲酰化绿色串联催化工艺中,也可以直接将烯烃合成醇、胺、缩醛、α,β-不饱和醛等产物,串联催化工艺对提高铑的利用率、催化性能等方面同样具有重要的研究与应用价值.本文以铑催化剂为主线,重点综述了铑催化剂在氢甲酰化反应中的高活性应用和"一锅法"实现烯烃的氢甲酰化-加氢、氢甲酰化-还原胺化、氢甲酰化-缩醛化、氢甲酰化-羟醛缩合等串联催化反应.

A spinel-alumina inert oxide supported gold catalyst with high Au dispersion and excellent CO oxidation activity was developed by a deposition-precipitation method. The activation atmosphere could tune the reaction pathway by adjusting the amount of surface adsorbed water species, thus transforming the reaction intermediates from HCO3- or CO32- to COOH.

Gold nanoparticles have a high activity for CO oxidation, making them suitable to be used in a CO(2)laser which maintains its efficiency and stabilityviathe recombination of CO and O(2)produced by the CO(2)decomposition. However, the high concentration of CO(2)in the working environment greatly reduces the activity of the catalyst and makes the already unstable gold nanoparticles even more so. A novel Au/Ce-Co-O-x/Al(2)O(3)gold catalyst, prepared by a deposition precipitation method in this study, displays high activity and good stability for CO oxidation in a simulated atmosphere of a CO(2)laser with the feed gases containing a high concentration of CO(2)up to 60 vol% but a low concentration of O(2)for the stoichiometric reaction with CO. An excellent performance for CO oxidation under CO2-rich conditions could be achieved by decorating the surface of the Al(2)O(3)support with Ce-Co composite oxides. The strong interaction between gold and the composite support, accompanied by the increase of labile lattice oxygen species and the decrease of surface basicity, led to a high CO oxidation rate and resistance towards CO(2)poisoning.

Developing of high-performance and low-cost electrocatalysts is of great significance to reduce the overpotential and accelerated the reaction rate of oxygen evolution in water splitting and related energy conversion applications. Herein, Fe, O-dual doped Ni2P (Fe, ONi2P) nanoarray is successfully synthesized on carbon cloth demonstrating enhanced electrocatalytic activity and stability for oxygen evolution reaction (OER) under alkaline media. The as-synthesized Fe, ONi2P nanoarray exhibits obviously improved OER performance with a low overpotential of 210 mV at 10 mA cm−2 current density and a Tafel slope of 48 mV dec−1, as well as long-term durability. The strong coupling interaction induced changes in electronic structure lead to relatively higher oxidation state and stronger oxidation ability of the Fe, ONi2P nanoarray, together with the high electrochemical surface area and good conductivity contribute to the superior OER performance. This work highlights the anion-cation dual doping strategy may be an effective method for fabrication of catalysts relating to energy conversion applications.

The interfacial sites of supported metal catalysts are often critical in determining their performance. Single-atom catalysts (SACs), with every atom contacted to the support, can maximize the number of interfacial sites. However, it is still an open question whether the single-atom sites possess similar catalytic properties to those of the interfacial sites of nanocatalysts. Herein, we report an active-site dependent catalytic performance on supported gold single atoms and nanoparticles (NPs), where CO oxidation on the single-atom sites is dramatically promoted by the presence of H2O whereas on NPs' interfacial sites the promoting effect is much weaker. The remarkable H2O promoting effect makes the Au SAC two orders of magnitude more active than the commercial three-way catalyst. Theoretical studies reveal that the dramatic promoting effect of water on SACs originates from their unique local atomic structure and electronic properties that facilitate an efficient reaction channel of CO + OH.

A novel Au/Fe–V–Ox/Al2O3 catalyst displayed remarkable activity and good stability for CO oxidation in the simulated atmosphere of a CO2 laser with high CO2 levels up to 60 vol% and stoichiometric or even lower O2/CO ratio. The improved surface labile lattice oxygen on the FeOx and VOx modified Al2O3 plays a crucial role in its outstanding performance for the CO oxidation reaction in an oxygen-poor atmosphere.

ABSTRACT Herein, polystyrene/polyaniline/Pd (PS/PANI/Pd) core‐shell composite catalysts were prepared by a facile swelling‐diffusion‐interfacial polymerization method. PS microparticles were firstly prepared by dispersion polymerization and were swollen by aniline monomer without any surface modification. H 2 PdCl 4 acid was used as palladium precursor. The was adsorbed on the surface of aniline‐swollen PS microparticles because of the electrostatic attraction between and anilinium positive ions protonated by H + , which was diffused from the aniline‐swollen PS microparticles. Then HCl solution was added to control the diffusion rate of anilinium positive ions and ammonium persulfate (APS) was used to polymerize the anilinium ions to get PANI shell. Due to the redox activity between PANI and Pd ions, Pd nanoparticles can be in situ formed on the surfaces of PS. Therefore, the core‐shell PS/PANI/Pd composite catalysts were obtained. The morphology and structure of the obtained composites was characterized by TEM, FT‐IR and EDX. Results showed that the products presented excellent catalytic properties for the reduction of 4‐nitrophenol (4‐NP) to 4‐aminophenol (4‐AP) in the presence of NaBH 4 by virtue of the interaction between Pd nanoparticles and conducive PANI shell. The catalytic reaction obeyed the pseudo‐first‐order reaction equations and the reaction rate constants were also calculated in this article. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44812.

The CO2 laser is a kind of widely used gas laser, but during the running time its working gas happened easily the plasma induction which lead to the chemical reactions and produce harmful ingredients, mainly were CO and O2, therefore the output power of CO2 laser decreased gradually.The catalytic method to eliminate harmful components such as CO is a high efficiency and low cost strategy to deal with the decline of the laser power.This paper describes the working principle of CO2 laser and the existing problems, and briefly summarizes the domestic and international research status of solid catalyst for CO2 laser.Moreover, it focus on the prospects of the nano-Au catalysts in the application of CO2 laser, and provides a new idea for the research and development of solid catalyst for efficient closed CO2 laser.

A novel Au/Fe–V–Ox/Al2O3 displays remarkable activity and good stability for CO oxidation in simulated atmosphere of CO2 laser. The higher Au dispersion and more labile lattice oxygen after modification contributed to its outstanding performance.

Shandong Applied Research Center of Nan Chemistry & Chemical Engineering, Yan E-mail: Qicx@ytu.edu.cn; Fax: +86 535 691 Research Center for Gold Chemistry, Gr Sciences, Tokyo Metropolitan University, To Japan Synchrotron Radiation Research Ins Japan † Electronic supplementary information (E of XRD, HAADF-STEM, XANES and Rama ‡ These authors contributed equally to th Cite this: RSC Adv., 2017, 7, 38780

A series of gold-based catalysts supported by Fe-La-Al2O3 composite doped with various amounts of copper were prepared using a modified deposition-precipitation method. Investigations were carried out based on the reaction of the preferential carbon monoxide oxidation (CO-PROX) in H-2-rich stream and CO oxidation at low temperatures in an O-2-rich stream as a reference to examine the effects of copper on the catalytic performance. The high dispersion of gold nanoparticles in alumina-based support, the formation of Au-Cu alloy, and the close contacts of these neat or alloyed nanoparticles with CuO species, making Au partially positively charged, were examined with H-2-TPR, XPS, and HRTEM-FFT techniques. Gold catalysts were obtained with very promising performance for polymer electrolyte membrane fuel cell with positive results in activity, CO2 selectivity, and thermal stability and long-term storage and online stability. Although H-2 addition decreased the rate of CO oxidation over the studied gold catalysts, the activity and selectivity in CO2 formation were continuously improved with an increase in copper loading. (C) 2016 Elsevier B.V. All rights reserved.

We reported a novel and simple strategy to construct core-shell composite microspheres with fly ash (FA) and Au nanoparticles embedded in polypyrrole (PPy) chains. In an acid medium, activation of FA microspheres, synthesization of Au nanoparticles, and polymerization of PPy were synergistically achieved in one-step green process. The physicochemical characteristics of the Au-PPy/FA composite microspheres were studied by SEM, TEM, FTIR, XRD, TGA and VSM. In the presence of NaBH4 as a reducing agent, the Au-PPy/FA composite microspheres exhibited highly catalytic efficiency in reduction of nitrophenol to aminophenol. The reaction rate constants were calculated through the pseudo-first-order kinetic equation by using the excess amount of NaBH4. For the two isomers of nitrophenol, the reduction rates were particularly investigated and followed the order: 4-nitrophenol > 2-nitrophenol. The electronic interaction between Au nanoparticles and PPy chains plays an important role for the highly catalytic efficiency of the Au-PPy/FA. A possible reaction mechanism for the reduction process was also emphasized. (C) 2016 Elsevier B.V. All rights reserved.