Journal Sciences News
The Surgeon
June 2018
Carbazole-decorated covalent triazine frameworks: Novel nonmetal catalysts for carbon dioxide fixation and oxygen reduction reaction
Publication date: June 2018
Source:Journal of Catalysis, Volume 362 Author(s): Wenguang Yu, Shuai Gu, Yu Fu, Shaohui Xiong, Chunyue Pan, Younian Liu, Guipeng Yu Task-specific carbazole-based covalent triazine frameworks (CTF-CSUs) have been designed and prepared. The obtained materials could serve as excellent catalysts for both CO2 chemical fixation and oxygen reduction reaction (ORR). Results shown that using CTF-CSUs as catalysts, the cycloaddition reactions between CO2 and epoxides were readily achieved with extremely high yields (99%) under mild conditions (0.1
June 2018
Palladium-catalyzed carbonylative bis(indolyl)methanes synthesis with TFBen as the CO source
Publication date: June 2018
Source:Journal of Catalysis, Volume 362 Author(s): Xinxin Qi, Han-Jun Ai, Ning Zhang, Jin-Bao Peng, Jun Ying, Xiao-Feng Wu An efficient and convenient palladium-catalyzed carbonylative procedure for the synthesis of bis(indolyl)methanes has been established for the first time. With TFBen (benzene-1,3,5-triyl triformate) as the solid CO source, aryl iodides and indoles were transformed into the corresponding bis(indolyl)methane derivatives in moderate to excellent yields.

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June 2018
Combined quantitative FTIR and online GC study of Fischer-Tropsch synthesis involving co-fed ethylene
Publication date: June 2018
Source:Journal of Catalysis, Volume 362 Author(s): Andrew I. McNab, Alan J. McCue, Davide Dionisi, James A. Anderson Combined quantitative in-situ FTIR and online gas chromatography have been applied to assess the effect of co-feeding ethylene on the length and nature of the hydrocarbon species formed on cobalt catalysts and the detected reaction products during Fischer-Tropsch synthesis. Reaction data showed that co-feeding ethylene leads to a decrease in methane selectivity and an increase in selectivity to C5-6 products. Comparison of the average length of the adsorbed species during reactions, in the presence and absence of co-fed ethylene reveals that ethylene may be incorporated into species which re-adsorb to the
June 2018
Additive free, room temperature direct homogeneous catalytic carbon dioxide hydrogenation in aqueous solution using an iron(II) phosphine catalyst
Publication date: June 2018
Source:Journal of Catalysis, Volume 362 Author(s): Mickael Montandon-Clerc, G
June 2018
Ethylene versus ethane: A DFT-based selectivity descriptor for efficient catalyst screening
Publication date: June 2018
Source:Journal of Catalysis, Volume 362 Author(s): Lang Xu, Eric E. Stangland, Manos Mavrikakis The production of ethylene without its hydrogenation to ethane is a challenge for several catalytic processes. Here, we present a catalyst screening scheme, where the Gibbs free energy difference between the ethylene hydrogenation barrier and ethylene desorption energy is defined as a descriptor for ethylene selectivity. Using plane-wave, dispersion-corrected DFT calculations, we evaluated the descriptor values over the (111) facets of Pt, Pd, and Cu as well as a series of Pt- and Pd-based bimetallic alloys. Our predicted descriptor values indicate that the addition of a Group IB metal (Cu, Ag, or Au) to Pt or Pd improves ethylene selectivity. Ag induces the most significant improvement at 50% while Au has the strongest effect at 75% atomic composition. Pd-based alloys exhibit superior ethylene selectivity over their Pt-based counterparts. Our descriptor model offers an efficient method for the initial screening of catalysts with improved ethylene selectivity.

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June 2018
Mechanistic insight into cobalt-catalyzed stereodivergent semihydrogenation of alkynes: The story of selectivity control
Publication date: June 2018
Source:Journal of Catalysis, Volume 362 Author(s): Xiaotian Qi, Xufang Liu, Ling-Bo Qu, Qiang Liu, Yu Lan Selectivity control is a challenging and important subject in semihydrogenation of alkynes. Here, a combined theoretical and experimental study was performed to reveal the origin of the chemo- and stereoselectivity in cobalt-catalyzed stereodivergent semihydrogenation of alkynes. Three NNP and PNP type pincer ligands were considered in calculation. The computational results show that over-reduction of the alkene is forbidden in this catalytic system because the alkylcobalt(I) intermediate formed by alkene insertion prefers to undergo
June 2018
Microcalorimetric adsorption and infrared spectroscopic studies of supported nickel catalysts for the hydrogenation of diisopropylimine to diisopropylamine
Publication date: June 2018
Source:Journal of Catalysis, Volume 362 Author(s): Lidan Deng, Jianxin Zhu, Hui Chen, Hui Wang, Jianyi Shen Diisopropylimine (DIPI) was used as a probe molecule to investigate the hydrogenation of CN on the Ni/Al2O3, Ni/LaAlO and Ni/LaOx catalysts. Microcalorimetric adsorption and infrared spectroscopy were applied to determine the surface bond strengths and structures of the reactant and product. It was found that the acidic support favored the adsorption and activation of DIPI and H2 on Ni, leading to the increased activity (TOF) for the hydrogenation of DIPI, while the basic support promoted the dehydrogenation of the amine product on Ni, being unfavorable for the hydrogenation of DIPI. In particular, the conversion of DIPI was significantly increased when isopropanol (IPA) was used as a solvent, due to the hydrogen transfer reaction (HTR) between IPA and DIPI, which was further evidenced by the infrared spectrum of co-adsorbed IPA and DIPI.

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June 2018
NHC-copper complexes immobilized on magnetic nanoparticles: Synthesis and catalytic activity in the CuAAC reactions
Publication date: June 2018
Source:Journal of Catalysis, Volume 362 Author(s): I. Misztalewska-Turkowicz, K.H. Markiewicz, M. Michalak, A.Z. Wilczewska A series of N-heterocyclic carbene copper(I) and rare copper(II) complexes (NHCCuCl or NHCCuCl2) were covalently immobilized directly on the surface of magnetic nanoparticles (MNPs) for the first time. The physicochemical properties were investigated by a broad range of techniques, including SEM and TEM microscopy, and TG analysis. The supported complexes exhibited excellent activity in the Huisgen cycloaddition with in situ generated azides. Unexpectedly, a direct comparison of NHCCuCl and NHCCuCl2 complexes anchored to the magnetic nanoparticles confirmed the higher activity of the latter for the formation of 1,2,3-triazoles, also under ascorbate-free conditions.

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June 2018
Time evolution of the CO2 hydrogenation to fuels over Cu-Zr-SBA-15 catalysts
Publication date: June 2018
Source:Journal of Catalysis, Volume 362 Author(s): Aylin Atakan, Edvin Erdtman, Peter M
June 2018
Dichlorovanadium(IV) diamine-bis(phenolate) complexes for ethylene (co)polymerization and 1-olefin isospecific polymerization
Publication date: June 2018
Source:Journal of Catalysis, Volume 362 Author(s): Marzena Bia
June 2018
One-step solid state synthesis of PtCo nanocubes/graphene nanocomposites as advanced oxygen reduction reaction electrocatalysts
Publication date: June 2018
Source:Journal of Catalysis, Volume 362 Author(s): Chunyong He, Shengkai Zhang, Juzhou Tao, Pei Kang Shen Here, we report the synthesis of PtCo nanocubes with core–shell structure on graphene surface by a novel solid state method. Since no organic agent and surfactant was used during the synthesis process, the PtCo nanocubes surface is definite clean. The mean grain size of PtCo nanocubes is just about 5
June 2018
Mild-acid-assisted thermal or hydrothermal dealumination of zeolite beta, its regulation to Al distribution and catalytic cracking performance to hydrocarbons
Publication date: June 2018
Source:Journal of Catalysis, Volume 362 Author(s): Wennian Wang, Wei Zhang, Yunlei Chen, Xiaodong Wen, Hao Li, Delin Yuan, Qiaoxia Guo, Shenyong Ren, Xinmei Pang, Baojian Shen The synthesized nanoscale beta zeolites (SiO2/Al2O3
June 2018
Controlled formation of iron carbides and their performance in Fischer-Tropsch synthesis
Publication date: June 2018
Source:Journal of Catalysis, Volume 362 Author(s): Tim A. Wezendonk, Xiaohui Sun, A. Iulian Dugulan, Arno J.F. van Hoof, Emiel J.M. Hensen, Freek Kapteijn, Jorge Gascon Iron carbides are unmistakably associated with the active phase for Fischer-Tropsch synthesis (FTS). The formation of these carbides is highly dependent on the catalyst formulation, the activation method and the operational conditions. Because of this highly dynamic behavior, studies on active phase performance often lack the direct correlation between catalyst performance and iron carbide phase. For the above reasons, an extensive in situ M
May 2018
Effects of Ag promotion and preparation method on cobalt Fischer-Tropsch catalysts supported on silica-modified alumina
Publication date: June 2018
Source:Journal of Catalysis, Volume 362 Author(s): Mahmood Rahmati, Baiyu Huang, Landon M. Schofield, Thomas H. Fletcher, Brian F. Woodfield, William C. Hecker, Calvin H. Bartholomew, Morris D. Argyle A series of silver-promoted, 20
May 2018
Editorial Board
Publication date: May 2018
Source:Journal of Catalysis, Volume 361

May 2018
Additive-free aerobic oxidative dehydrogenation of N-heterocycles under catalysis by NiMn layered hydroxide compounds
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Weiyou Zhou, Qianyun Tao, Fu'an Sun, Xinbai Cao, Junfeng Qian, Jie Xu, Mingyang He, Qun Chen, Jianliang Xiao NiMn layered hydroxide compounds have been found to be efficient catalysts for the oxidative dehydrogenation of N-heterocycles by molecular oxygen under mild conditions. Various tetrahydroquinoline derivatives and some other N-heterocycles have been found to be tolerated by the catalytic system. A synergistic effect between Ni and Mn has been observed in the reaction. A kinetic study concluded that the dehydrogenation of 1,2,3,4-tetrahydroquinoline is a first-order reaction, and an apparent activation energy of 113
May 2018
Nondestructive construction of Lewis acid sites on the surface of supported nickel phosphide catalysts by atomic-layer deposition
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Guoxia Yun, Qingxin Guan, Wei Li In this paper, we have developed a new strategy to construct the acidic sites on the surface of supported transition-metal phosphide catalysts, which could precisely control the deposition of the Al2O3 atomic layer through atomic-layer deposition (ALD). A series of supported nickel phosphide catalysts decorated with Al2O3 film were prepared and characterized. The results show that Al2O3 film was deposited on the surface of the catalyst via AlOSi bonding, which does not affect or alter the characteristics of the as-prepared nickel phosphide phase. Most importantly, among all the Ni2P-based catalysts, the Ni2P/SiO2-ALD catalyst with 10 Al2O3 layers possesses the optimal performance in hydrodesulfurization and hydrodearomatization reactions. In particular, superior hydrogenation performances were considered to be strongly related to a synergistic effect between nickel phosphide and the modulated acidic property. This precise stepwise ALD strategy opens a convenient route and provides a prospective design guideline for constructing high-performance hydrogenation catalysts.

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May 2018
Mn promoted Co catalysts for Fischer-Tropsch production of light olefins – An experimental and theoretical study
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Eirik
May 2018
Selective oxidation of amines using O2 catalyzed by cobalt thioporphyrazine under visible light
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Juanjuan Jin, Changjun Yang, Bingguang Zhang, Kejian Deng A highly efficient oxidation of amines including primary and secondary amines into imines using O2 as the oxidant was realized by cobalt tetra(2-hydroxymethyl-1,4-dithiin)porphyrazine (CoPz(hmdtn)4) under irradiation of visible light (
May 2018
Exploitation of differential electronic densities for the stereoselective reduction of ketones bearing a masked amino surrogate
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Renta Jonathan Chew, Martin Wills A tethered ruthenium-TsDPEN catalyst is employed for the facile catalytic asymmetric reduction of
May 2018
Identification of key mechanics in the ruthenium catalyzed synthesis of N,N-dimethylformamide from carbon dioxide in biphasic solvent systems
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Ren
May 2018
The role of water in the reusability of aminated silica catalysts for aldol reactions
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Anton De Vylder, Jeroen Lauwaert, Dolores Esquivel, Dirk Poelman, Jeriffa De Clercq, Pascal Van Der Voort, Joris W. Thybaut The reusability of methylaminopropyl active sites grafted on mesoporous amorphous silica, either with cooperative silanol groups or trimethylsilated, was assessed in the aldol reaction of acetone with 4-nitrobenzaldehyde. Raman, 13C NMR, and UV–Vis spectroscopy demonstrated the presence of stable enamines on the spent catalysts. These enamines are produced as a side product from iminium intermediates in the catalytic cycle. Water co-feeding enhances the desorption of the iminium intermediates and, hence, suppresses the formation of these stable enamine species. The reusability of the cooperative catalyst increased to 70% with co-feeding 0.69
May 2018
Active sites speciation of supported CoMoS phase probed by NO molecule: A combined IR and DFT study
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Fabien Caron, Micka
May 2018
Impact of the Cu2O microcrystal planes on active phase formation in the Rochow reaction and an experimental and theoretical understanding of the reaction mechanism
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Jing Li, Li-Li Yin, Yongjun Ji, Hezhi Liu, Yu Zhang, Xue-Qing Gong, Ziyi Zhong, Fabing Su In heterogeneous catalysis, on one hand, people always want to know about reaction details, such as what the most active phase is, how it is formed, and what is the reaction mechanism. On the other hand, it is still very challenging to probe these reaction details, particularly at high reaction temperatures and pressures. Here, we report the microcrystal plane-controlled catalytic performance on well-defined Cu2O cube, octahedron, and rhombic-dodecahedron catalysts in the Rochow reaction. It was found that the Cu2O cube exposing {1
May 2018
Polydopamine supported palladium nanoparticles: Highly efficient catalysts in Suzuki cross-coupling and tandem Suzuki cross-coupling/nitroarene reductions under green reaction conditions
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Attila Kunfi, Zolt
May 2018
Enhanced ethylene selectivity and stability of Mo/ZSM5 upon modification with phosphorus in ethane dehydrogenation
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Zhonghai Ji, Houfu Lv, Xiulian Pan, Xinhe Bao Nonoxidative conversion of ethane to ethylene and/or BTX (benzene, toluene, and xylene) suffers rapid deactivation due to coke deposition. We report here the effects of phosphorus modification on the stability and activity of Mo/ZSM5 for nonoxidative conversion of ethane. The results show that the ethylene and BTX yield and stability are significantly enhanced upon modification with 2.5
May 2018
One-pot synthesis of secondary amine via photoalkylation of nitroarenes with benzyl alcohol over Pd/monolayer H1.07Ti1.73O4·H2O nanosheets
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Yujie Song, Hao Wang, Shijing Liang, Yan Yu, Liuyi Li, Ling Wu The photoalkylation of nitroarenes with benzyl alcohols in one pot at room temperature and 1
May 2018
La-Metal-Organic Framework incorporating Fe3O4 nanoparticles, post-synthetically modified with Schiff base and Pd. A highly active, magnetically recoverable, recyclable catalyst for CC cross-couplings at low Pd loadings
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Gang Xiong, Xiao-Ling Chen, Li-Xin You, Bao-Yi Ren, Fu Ding, Ileana Dragutan, Valerian Dragutan, Ya-Guang Sun Unprecedented post-synthetic modification (PSM) applied on a new La-MOF containing Fe3O4 nanoparticles (NPs), via Schiff base build-up (with pyridine-2-carboxaldehyde) and PdCl2 coordination, proved to be an advantageous strategy to produce a superior heterogeneous catalyst for Suzuki-Miyaura CC bond formation. The Fe3O4@La-MOF-Schiff base-Pd ensemble (characterized by PXRD, EDS, TEM, HAADF-STEM, VSM, TGA) showed very active, quite stable, magnetically recoverable and reusable in coupling of bromo- or iodoaryls with arylboronic acids, affording practically quantitative yields of biaryls (>99%) and high TONs and TOFs. The catalyst has been recycled up to 12 times without significant loss of the catalytic activity. A synergistic cooperativity between Pd and the oxophilic La nodes, through the organic linker, is responsible for enhancing the catalyst activity and stability.

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May 2018
Characterization of iron contamination on equilibrium fluid catalytic cracking catalyst particles
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Hui Jiang, Kenneth J. Livi, Shankhamala Kundu, Wu-Cheng Cheng Iron poisoning is a well-known problem for fluid catalytic cracking catalysts. To better understand this issue, several characterization techniques were used to examine a catalyst sample from a commercial unit. Under SEM-EDX, most cross sections of the catalyst particles exhibited iron nodule rims enriched with Fe, other contaminant metals, and Si. Scanning TEM X-ray mapping further confirmed that, compared to the inside of a catalyst particle, the surface layer was enriched in Si and contaminant metals, while depleted in Al. This catalyst had high frequency-dependent magnetic susceptibility, suggesting that some or all of the iron-bearing species should be in the nanometer size range. In TEM, the nodules were found to consist of Fe-bearing nanoparticles, imbedded in an amorphous matrix. The nanoparticles were also enriched in Mg, Ni or Ca, while the matrix was dominated by Si and minor Al. Selected area electron diffraction pattern indicated that these iron enriched nanoparticles had the spinel structure. These results should shed light on iron poisoning issues in FCC units.

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May 2018
A dual-templating synthesis strategy to hierarchical ZSM-5 zeolites as efficient catalysts for the methanol-to-hydrocarbons reaction
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Lingqian Meng, Xiaochun Zhu, Wannaruedee Wannapakdee, Robert Pestman, Maarten G. Goesten, Lu Gao, Arno J.F. van Hoof, Emiel J.M. Hensen A novel dual-templating synthesis strategy is presented to obtain hierarchical ZSM-5 zeolite using a combination of known structure-directing agents for ZSM-5 synthesis and C16H33-[N+-methylpiperidine] (C16MP) as mesoporogen. C16MP is a cheap surfactant, which can be obtained in a single step by alkylation of N-methylpiperidine. The zeolite materials were extensively characterized for their textural and acidic properties and evaluated on the basis of their ability to convert methanol to hydrocarbons. Bulk and nanosheet (di-quaternary ammonium surfactant) ZSM-5 zeolites served as reference materials. Hierarchical ZSM-5 zeolite can be obtained in this way with diethylamine, n-propylamine, 1,4-diaminobutane, 1,6-diaminohexane. In particular, the combination with diethylamine afforded a material that displayed similar performance in the methanol-to-hydrocarbons reaction as nanosheet ZSM-5. The optimum ZSM-5 zeolite is highly crystalline, contains a large mesopore volume and few silanol groups and external Br
May 2018
l-serine-functionalized montmorillonite decorated with Au nanoparticles: A new highly efficient catalyst for the reduction of 4-nitrophenol
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Mariana Rocha, Paula Costa, Carlos A.D. Sousa, Clara Pereira, Jos
May 2018
Tuning the Fischer–Tropsch reaction over CoxMnyLa/AC catalysts toward alcohols: Effects of La promotion
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Ziang Zhao, Wei Lu, Hejun Zhu, Wenda Dong, Yuan Lyu, Tao Liu, Xingkun Chen, Yuqing Wang, Yunjie Ding Selective synthesis of mixed alcohols from syngas (CO
May 2018
Peptide templated Au@Pd core-shell structures as efficient bi-functional electrocatalysts for both oxygen reduction and hydrogen evolution reactions
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Zhuo Zong, Kebin Xu, Dongliang Li, Zhenghua Tang, Wei He, Zhen Liu, Xiufang Wang, Yong Tian Bimetallic core-shell nanostructures have been gaining considerable research attentions recently, mainly thanks to their versatile applications in many fields, including catalysis, electrocatalysis, electronic, sensing and so on. Herein, we demonstrate a peptide templated Au@Pd core-shell structure for both oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER). By employing peptide sequence FlgA3 as surface capping agent, core-shell structure with Pd nanoparticles coated on the surface of Au nanoparticles were prepared. The Au@Pd core-shell structures demonstrated effective electrocatalytic activities toward both ORR and HER, whereas the catalytic activity was optimized by tuning the Pd-to-Au ratio. Among a series of samples tested, we discovered that the Au@Pd1.0 sample exhibited the best ORR activity, superior to that of Pt/C and Pd/C, while its HER activity was also among the finest, close to that of Pt/C and Pd/C. The Au@Pd1.0 sample also exhibited remarkable stability beyond Pt/C and Pd/C in both ORR and HER. Such intriguing electrocatalytic performances are attributed to the core-shell structure induced lattice strain. The results offer reliable pathway for designing peptide templated core-shell bimetallic nanostructures as dual or multiple functional electrocatalysts with excellent electrocatalytic activities and longevity.

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May 2018
Synthesis and characterization of bundle-shaped ZSM-22 zeolite via the oriented fusion of nanorods and its enhanced isomerization performance
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Zhiqiang Chen, Suyao Liu, Honghao Wang, Qiang Ning, Huaike Zhang, Yifeng Yun, Jie Ren, Yong-Wang Li ZSM-22 zeolites with needle-shaped, bundle-shaped, as well as bulk-shaped morphologies are prepared by tuning hydrothermal synthesis conditions. These as-synthesized zeolites have similar crystallinity, Si/Al ratios and micropores revealed by XRD, XRF and BET. However, the oriented fusion of nanorods in the bundle-shaped ZSM-22 zeolite leads to the formation of more framework aluminum atoms over T1
May 2018
Cycloketone condensation catalyzed by zirconia: Origin of reactant selectivity
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Mi Wan, Decheng Liang, Li Wang, Xiangwen Zhang, Dong Yang, Guozhu Li Aldol condensation of cycloketone(s) is an efficient reaction path to synthesize polycyclic compounds via CC bond formation. In this work, aldol condensation of cyclopentanone and/or cyclohexanone over monoclinic ZrO2 has been investigated by combination of experiments and DFT calculations. Both self-condensation and cross-condensation of cyclopentanone and/or cyclohexanone were carried out at 130
May 2018
Deactivation of Pt/KL catalyst during n-heptane aromatization reaction
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Ke Li, Qiang Chang, Junqing Yin, Chunli Zhao, Lihua Huang, Zhichao Tao, Yifeng Yun, Chenghua Zhang, Hongwei Xiang, Yong Yang, Yongwang Li The deactivation of Pt/KL catalyst during n-heptane aromatization reaction was investigated. The activity fell quickly, especially in the initial stage. The fresh, the used and the regenerated catalysts were characterized by N2 physisorption, HADDF-STEM, TGA, UV-Raman, etc. The rapid deactivation is attributed to declined accessibility to Pt active sites because of coke deposition. GC-MS analysis revealed that the coke species are polycyclic aromatic hydrocarbons (PAHs). The dimensions of coke molecules and the coke volumes of used catalysts were estimated via DFT calculations. The variation of the contents of different coke species with reaction time implies a shape-selective transformation under micropore constraints. This, together with the XPS-determined depth profile of the coke in the used catalyst, indicates most of the coke was internally encased near the micropore openings. Quantitative evaluation concerning the influence of coke deposition on micropore volume confirms severe channel blockage by coke.

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May 2018
Triple Ni-Co-Mo metal sulfides with one-dimensional and hierarchical nanostructures towards highly efficient hydrogen evolution reaction
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Zi-Zhang Liu, Xiao Shang, Bin Dong, Yong-Ming Chai Designing multi-transition metal-based sulfides holds promising in alkaline water electrolysis, whereas selecting proper candidates and facile building strategy remain challengeable. Herein, based on previous theory of combining 3d-transition metal (NiCo) with non-3d-transition metal (Mo) to lower hydrogen-adsorption energy barriers, we develop an indirect access to NiCoMo sulfides supported by nickel foam (CoMoO-S/NF) with one dimensional (1 D) and hierarchical nanostructures. In the first step, the metal oxides as precursor frameworks are designed as one-dimensional (1 D) nanostructures comprising interwoven nanosheets. The unique structure not only provides the large surface areas for exposing abundant active sites, but also improves the contact between catalyst/interface and facilitates the mass or charge transportation. Besides, the ternary metals are supposed to generate synergistic effect to boost hydrogen evolution reaction (HER) properties of CoMoO-S/NF via sulfurization in the second step. Furthermore, CoMoO-S/NF demonstrates high electrocatalytic performances with structural stability in long-term HER process. Therefore, the two-step building of ternary transition metal sulfides may be provide applications for various transition metal materials with unique architecture and high efficiency in alkaline HER.

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May 2018
Unraveling the sigmoidal profiles in Fenton catalysis: Toward mechanistic elucidation
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Daniele Scheres Firak, Elisa S. Orth, Patricio Peralta-Zamora Fenton reactions are widely known and have been employed to degrade different pollutants in various environmental matrices. However, some controversies related to the Fenton mechanism remain unresolved. Although not comprehensively understood, kinetic sigmoidal profiles with an initial induction period have frequently been reported for Fenton systems. A thorough kinetic study was carried out at different temperatures involving Fenton reactions promoted by Fe3+ and Fe2+ and under the influence of radical scavengers. Catalysis supported by Fe2+ displayed the usual pseudo-first-order profile, while Fe3+ catalysis showed a sigmoidal pattern. The sigmoidal profiles were correlated to a pseudo-elementary autocatalytic mechanism developed by Finke and Watzky (F–W). The use of the F–W equation indicates that a certain amount of oxidative species must be generated to promote the substrate degradation. This correlation is a breakthrough in the understanding of Fenton catalysis.

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May 2018
Functionalizing carbon nitride with heavy atom-free spin converters for enhanced 1O2 generation
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Wenting Wu, Congcong Han, Qinhua Zhang, Qinggang Zhang, Zhongtao Li, David J. Gosztola, Gary P. Wiederrecht, Mingbo Wu Carbon nitride as a metal-free conjugated polymer exhibits an intriguing prospect for the design of advanced photosensitizers for singlet oxygen (1O2) generation. However, the intersystem crossing (ISC) process is quite insufficient in carbon nitride, limiting the 1O2 generation. Here, we report a facile and general strategy to confined benzophenone as a heavy atom-free spin converter dopant in carbon nitride via the facile copolymerization. With proper energy level matching between the heavy atom-free spin converter and various ligands based on carbon nitride precursors, the proper combination can decrease the singlet-triplet energy gap (
May 2018
Combination of transition metal Rh-catalysis and tautomeric catalysis through a bi-functional ligand for one-pot tandem methoxycarbonylation-aminolysis of olefins towards primary amides
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Peng Wang, Lei Liu, Zhoujie Luo, Qing Zhou, Yong Lu, Fei Xia, Ye Liu Combination of transition metal catalysis with organocatalysis in ways of synergetic catalysis, cooperative catalysis, or/and sequential catalysis has been emerged as a powerful strategy to promote organic transformations that cannot be achieved by each individual independently. Herein, a new protocol for the synthesis of primary amides from olefins, CO and NH3 through one-pot tandem methoxycarbonylation-aminolys was presented over a bi-functional ligand (L1) based rhodium catalyst with functions of co-catalysis. L1 is composed of the phosphino-fragment and the amino-/imino- tautomeric moiety. Then L1-based Rh-catalytic system demonstrated a combination of Rh-P transition metal catalysis and the tautomeric catalysis. In this tandem methoxycarbonylation-aminolysis, NH3 also served as a ligand to work together with the phosphino-fragment to synergetically modify the performance of Rh-catalyst responsible for the first-step methoxycarbonylation of olefin to generate the esters, and the Rh-tailed tautomeric catalyst was in charge of the subsequent aminolysis to generate the targeted primary amides.

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May 2018
Bimetallic AuPd alloy nanoparticles deposited on MoO3 nanowires for enhanced visible-light driven trichloroethylene degradation
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Yifan Zhang, Soo-Jin Park Photocatalytic oxidation reactions are regarded as promising green methods for the photodegradation of volatile organic compounds such as trichloroethylene. However, the low efficiency and selectivity of the existing photocatalysts limit practical applications of this technique. In this work, MoO3 nanowires were easily decorated with well-dispersed bimetallic Au–Pd alloyed nanoparticles (AuPd NPs) by a two-step wet-chemical strategy (hydrothermal and chemical reduction). The morphology, size, crystal structures, and mechanism of operation of the photocatalysts were investigated by a series of techniques (X-ray diffraction, scanning and transmission electron microscopy, and photoluminescence spectroscopy, etc.). Deposition of the AuPd NPs on the surface of the MoO3 nanowires led to a dramatic enhancement (11.5 times higher than that of the pure MoO3 nanowires) of the photocatalytic activity of the synthesized photocatalysts. This remarkable improvement of the activity can be attributed to the synergistic effect between Au and Pd NPs, which results in effective separation of the electron and holes and promotes the charge-separation efficiency. The enlarged specific surface area and enhanced stability of the catalysts also resulted in excellent photocatalytic performance. The developed photocatalysts are promising for the removal of volatile organic compounds.

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May 2018
PdAu@MIL-100(Fe) cooperatively catalyze tandem reactions between amines and alcohols for efficient N-alkyl amines syntheses under visible light
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Dengke Wang, Yating Pan, Lizhi Xu, Zhaohui Li PdAu@MIL-100(Fe), with PdAu alloy nanoparticles of ca. 1.7
May 2018
TiO2/MXene Ti3C2 composite with excellent photocatalytic CO2 reduction activity
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Jingxiang Low, Liuyang Zhang, Tong Tong, Baojia Shen, Jiaguo Yu Photocatalytic CO2 reduction for solar fuel production has received enormous attention due to its ability for solving both energy crisis and CO2 pollution. However, fabrication of cheap and efficient materials for photocatalytic CO2 reduction is still challenging. Herein, TiO2 nanoparticles (NPs) in situ grew on highly conductive MXene Ti3C2 through calcination method. And a unique rice crust-like structure was achieved through the uniform distribution of TiO2 nanoparticles on Ti3C2. This optimized TiO2/Ti3C2 composite exhibited a 3.7
May 2018
Catalytic ammonia combustion properties and operando characterization of copper oxides supported on aluminum silicates and silicon oxides
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Satoshi Hinokuma, Saaya Kiritoshi, Yusuke Kawabata, Kento Araki, Shun Matsuki, Tetsuya Sato, Masato Machida Although NH3 has recently been regarded as a renewable and carbon-free energy source, NH3 fuel has a high ignition temperature and its use results in the production of N2O/NOx. To overcome these issues, in this work, we focused on a novel catalytic combustion system and copper oxides (CuOx) catalysts supported on aluminum silicates (Al6O13Si2, 3Al2O3·2SiO2, 3A2S) and silicon oxides (SiO2). The preparation methods for 3A2S as a support material were optimized to achieve high catalytic NH3 combustion activity and high N2 (low N2O/NO) selectivity. Because the CuOx supported on 3A2S prepared by an alkoxide method and subsequent calcination at 1200
May 2018
Carbon nanotube-supported catalysts prepared by a modified photo-Fenton process for Fischer–Tropsch synthesis
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Haider Almkhelfe, Xu Li, Prem Thapa, Keith L. Hohn, Placidus B. Amama We demonstrate the use of a green catalyst precursor and oxidant in a modified photo-Fenton process for synthesis of efficient Fischer–Tropsch catalysts. The process yields small, stable, and well-dispersed catalyst nanoparticles (Fe or Co) on carbon nanotubes (CNTs) that do not require calcination due to the absence of foreign components (nitrate, chloride, or acetate) that must be removed during postsynthesis treatment. The synthesized catalysts were characterized by X-ray diffraction (XRD), N2 physisorption, H2 temperature-programmed reduction (H2 TPR), Raman spectroscopy, transmission electron microscopy (TEM), and inductively coupled plasma (ICP) spectroscopy. Results showed high catalyst dispersion and smaller catalyst particles with narrow particle-size distributions in comparison to catalysts synthesized by incipient wetness impregnation (IWI). Performance of CNT-supported catalysts (CO conversion, C5+ selectivity, and catalyst lifetime) prepared by the photo-Fenton process was evaluated during Fischer–Tropsch synthesis (FTS) and compared with that of CNT- and SiO2-supported catalysts synthesized via IWI. In general, a CNT-based Fe or Co catalyst, prepared by the photo-Fenton process, shows a higher performance at a lower FTS reaction temperature (200
May 2018
Aldol condensation among acetaldehyde and ethanol reactants on TiO2: Experimental evidence for the kinetically relevant nucleophilic attack of enolates
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Hongbo Zhang, Malek Y.S. Ibrahim, David W. Flaherty Combinations of rate measurements as functions of reactant pressures, in situ infrared spectroscopy, comparisons of kinetic isotope effects, and rate inhibition effects provide experimental evidence that aldol condensation of acetaldehyde proceeds by kinetically relevant nucleophilic attack of a reactive enolate upon an acetaldehyde molecule over anatase TiO2. Steady-state turnover rates of aldol condensation measured as a function of the pressures of C2H4O, C2H5OH, H2O, and H2 between 503
May 2018
PdSn/NiO/NaTaO3:La for photocatalytic ammonia synthesis by reduction of NO3
May 2018
Mechanism and microkinetics of methanol synthesis via CO2 hydrogenation on indium oxide
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): M.S. Frei, M. Capdevila-Cortada, R. Garc
May 2018
Strongly coupling of Co9S8/Zn-Co-S heterostructures rooted in carbon nanocages towards efficient oxygen evolution reaction
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Ziliang Chen, Miao Liu, Renbing Wu The design of efficient and nonprecious electrocatalysts towards oxygen evolution reaction (OER) is extremely essential for a wide range of renewable energy technologies but remains a grand challenge. Herein, a novel hybrid composite constructed from Co9S8/Co-doped ZnS (Zn0.8Co0.2S) nanorods with the atomic-level coupled nanointerface rooted in porous carbon polyhedra (Co9S8/Zn0.8Co0.2S@C) have been fabricated and investigated as a highly efficient electrocatalyst for OER. The composite catalyst can afford a current density of 10

Principles determining the activity of magnetic oxides for electron transfer reactions
Publication date: May 2018
Source:Journal of Catalysis, Volume 361 Author(s): Jose Gracia, Ryan Sharpe, Julen Munarriz Electrons in covalent oxides are fermions interacting through overlapping atomic orbitals, and quantum exchange interactions incorporate influential spin-dependent potentials in their electrocatalytic properties. The Goodenough-Kanamori rules explain the magnetic coupling between metals connected via ligands, known as super- (or double-) exchange interactions, which regulate their charge transport properties. To describe the electrocatalytic activity of magnetic metal oxides, we must extend their spin-dependent mechanisms of electron tunnelling to catalytic interfaces, because the exchange coupling between orbitals, in the catalysts and with the chemisorbed reactants, influences the kinetics of electron transfer reactions. The principles for developing magnetic coupling rules in electrocatalysis must guarantee spin passages, which are optimum for intrinsically degenerate configurations of the frontier orbitals oriented in the direction of the bonds at both sides of the Fermi level. A continuous energy landscape between the reactants and the catalyst minimizes the overpotentials during coherent redox electron tunnelling. Consequently, in this paper we derive the guidelines of the ferromagnetic (FM) exchange interactions, an extension of the Goodenough-Kanamori rules, to electrocatalytic interfaces, which anticipates minimum Gibbs energy of activation. We focus on the electronic coordinates, targeting reaction conditions where the electrons are the main energy carriers to trigger the steps; nonetheless they are inter-related with the atomic movements. We will use the oxygen evolution and reduction reactions as examples where quantum exchange interactions, a landmark of solid-state magnetism, and the chemistry of the triplet state O2 molecule, are crucial for optimum kinetics. One sentence summary: Delocalizing spin potentials facilitate the coherent propagation of electrons at covalent magnetic interfaces; this is a physical principle that links ferromagnetic exchange interactions, antibonding orbitals and optimum viable electrocatalysis: spintro-catalysis.

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