Low-Temperature Hydrogenation of Toluene Using an Iron-Promoted Molybdenum Carbide Catalyst

As an alternative to noble metal hydrogenation catalysts, pure molybdenum carbide displays unsatisfactory catalytic activity for arene hydrogenation. Precious metals such as palladium, platinum, and gold are widely used as additives to enhance the catalytic activities of molybdenum carbide, which severely limits its potential applications in industry. In this paper, iron-promoted molybdenum carbide was prepared and characterized by various techniques, including in situ XRD, synchrotron-based XPS and TEM. while the influence of Fe addition on catalytic performance for toluene hydrogenation was also studied. The experimental data disclose that a small amount of Fe doping strongly enhances catalytic stability in toluene hydrogenation, but the catalytic performance drops rapidly with higher loading amounts of Fe.

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Bimetallic Catalysts for Volatile Organic Compound Oxidation

Catalysts ◽

10.3390/catal10060661 ◽

2020 ◽

Vol 10 (6) ◽

pp. 661

Author(s):

Roberto Fiorenza

Keyword(s):

Bimetallic Catalysts ◽

Photocatalytic Oxidation ◽

Supported Catalysts ◽

Catalytic Performance ◽

Total Oxidation ◽

Voc Removal ◽

Bimetallic Systems ◽

Volatile Organic ◽

Potential Applications ◽

Catalytic Stability

In recent years, the impending necessity to improve the quality of outdoor and indoor air has produced a constant increase of investigations in the methodologies to remove and/or to decrease the emission of volatile organic compounds (VOCs). Among the various strategies for VOC elimination, catalytic oxidation and recently photocatalytic oxidation are regarded as some of the most promising technologies for VOC total oxidation from urban and industrial waste streams. This work is focused on bimetallic supported catalysts, investigating systematically the progress and developments in the design of these materials. In particular, we highlight their advantages compared to those of their monometallic counterparts in terms of catalytic performance and physicochemical properties (catalytic stability and reusability). The formation of a synergistic effect between the two metals is the key feature of these particular catalysts. This review examines the state-of-the-art of a peculiar sector (the bimetallic systems) belonging to a wide area (i.e., the several catalysts used for VOC removal) with the aim to contribute to further increase the knowledge of the catalytic materials for VOC removal, stressing the promising potential applications of the bimetallic catalysts in the air purification.

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Robust and efficient hydrogenation of carbonyl compounds catalysed by mixed donor Mn(I) pincer complexes

Nature Communications ◽

10.1038/s41467-020-20168-2 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Wenjun Yang ◽

Ivan Yu. Chernyshov ◽

Robin K. A. van Schendel ◽

Manuela Weber ◽

Christian Müller ◽

...

Keyword(s):

Noble Metal ◽

Crucial Role ◽

Carbonyl Compounds ◽

Catalytic Performance ◽

Hydrogen Atmosphere ◽

Pincer Complexes ◽

Catalyst Activation ◽

Hydrogenation Catalysts ◽

Induction Times

AbstractAny catalyst should be efficient and stable to be implemented in practice. This requirement is particularly valid for manganese hydrogenation catalysts. While representing a more sustainable alternative to conventional noble metal-based systems, manganese hydrogenation catalysts are prone to degrade under catalytic conditions once operation temperatures are high. Herein, we report a highly efficient Mn(I)-CNP pre-catalyst which gives rise to the excellent productivity (TOF° up to 41 000 h−1) and stability (TON up to 200 000) in hydrogenation catalysis. This system enables near-quantitative hydrogenation of ketones, imines, aldehydes and formate esters at the catalyst loadings as low as 5–200 p.p.m. Our analysis points to the crucial role of the catalyst activation step for the catalytic performance and stability of the system. While conventional activation employing alkoxide bases can ultimately provide catalytically competent species under hydrogen atmosphere, activation of Mn(I) pre-catalyst with hydride donor promoters, e.g. KHBEt3, dramatically improves catalytic performance of the system and eliminates induction times associated with slow catalyst activation.

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Ruling Factors in Cinnamaldehyde Hydrogenation: Activity and Selectivity of Pt-Mo Catalysts

Nanomaterials ◽

10.3390/nano11020362 ◽

2021 ◽

Vol 11 (2) ◽

pp. 362

Author(s):

Marta Stucchi ◽

Maela Manzoli ◽

Filippo Bossola ◽

Alberto Villa ◽

Laura Prati

Keyword(s):

Photoelectron Spectroscopy ◽

Pt Nanoparticles ◽

Carbon Support ◽

Catalytic Performance ◽

Acid Sites ◽

Hydrogenation Catalysts ◽

Cinnamaldehyde Hydrogenation ◽

Transmission Electron ◽

Heat Treated ◽

Heating Treatment

To obtain selective hydrogenation catalysts with low noble metal content, two carbon-supported Mo-Pt bimetallic catalysts have been synthesized from two different molybdenum precursors, i.e., Na2MoO4 and (NH4)6Mo7O24. The results obtained by X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) combined with the presence and strength of acid sites clarified the different catalytic behavior toward cinnamaldehyde hydrogenation. After impregnating the carbon support with Mo precursors, each sample was used either as is or treated at 400 °C in N2 flow, as support for Pt nanoparticles (NPs). The heating treatment before Pt deposition had a positive effect on the catalytic performance. Indeed, TEM analyses showed very homogeneously dispersed Pt NPs only when they were deposited on the heat-treated Mo/C supports, and XPS analyses revealed an increase in both the exposure and reduction of Pt, which was probably tuned by different MoO3/MoO2 ratios. Moreover, the different acid properties of the catalysts resulted in different selectivity.

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ChemInform Abstract: A New Generation of Homogeneous Arene Hydrogenation Catalysts

ChemInform ◽

10.1002/chin.199746262 ◽

2010 ◽

Vol 28 (46) ◽

pp. no-no

Author(s):

I. P. ROTHWELL

Keyword(s):

Hydrogenation Catalysts ◽

Arene Hydrogenation ◽

New Generation

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Stability of heterogeneous single-atom catalysts: a scaling law mapping thermodynamics to kinetics

npj Computational Materials ◽

10.1038/s41524-020-00411-6 ◽

2020 ◽

Vol 6 (1) ◽

Author(s):

Ya-Qiong Su ◽

Long Zhang ◽

Yifan Wang ◽

Jin-Xun Liu ◽

Valery Muravev ◽

...

Keyword(s):

Metal Atom ◽

Density Functional ◽

Activation Barrier ◽

Scaling Law ◽

Precious Metals ◽

Catalytic Performance ◽

Single Atom ◽

Atom Diffusion ◽

Computational Screening ◽

Metal Support

Abstract Heterogeneous single-atom catalysts (SACs) hold the promise of combining high catalytic performance with maximum utilization of often precious metals. We extend the current thermodynamic view of SAC stability in terms of the binding energy (Ebind) of single-metal atoms on a support to a kinetic (transport) one by considering the activation barrier for metal atom diffusion. A rapid computational screening approach allows predicting diffusion barriers for metal–support pairs based on Ebind of a metal atom to the support and the cohesive energy of the bulk metal (Ec). Metal–support combinations relevant to contemporary catalysis are explored by density functional theory. Assisted by machine-learning methods, we find that the diffusion activation barrier correlates with (Ebind)2/Ec in the physical descriptor space. This diffusion scaling-law provides a simple model for screening thermodynamics to kinetics of metal adatom on a support.

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Rationally designed indium oxide catalysts for CO2 hydrogenation to methanol with high activity and selectivity

Science Advances ◽

10.1126/sciadv.aaz2060 ◽

2020 ◽

Vol 6 (25) ◽

pp. eaaz2060 ◽

Cited By ~ 15

Author(s):

Shanshan Dang ◽

Bin Qin ◽

Yong Yang ◽

Hui Wang ◽

Jun Cai ◽

...

Keyword(s):

Density Functional ◽

Rational Design ◽

Density Functional Theory Calculations ◽

Catalytic Performance ◽

Oxide Catalysts ◽

Great Promise ◽

Experimental Realization ◽

Successful Case ◽

Catalytic Stability ◽

Pure Phases

Renewable energy-driven methanol synthesis from CO2 and green hydrogen is a viable and key process in both the “methanol economy” and “liquid sunshine” visions. Recently, In2O3-based catalysts have shown great promise in overcoming the disadvantages of traditional Cu-based catalysts. Here, we report a successful case of theory-guided rational design of a much higher performance In2O3 nanocatalyst. Density functional theory calculations of CO2 hydrogenation pathways over stable facets of cubic and hexagonal In2O3 predict the hexagonal In2O3(104) surface to have far superior catalytic performance. This promotes the synthesis and evaluation of In2O3 in pure phases with different morphologies. Confirming our theoretical prediction, a novel hexagonal In2O3 nanomaterial with high proportion of the exposed {104} surface exhibits the highest activity and methanol selectivity with high catalytic stability. The synergy between theory and experiment proves highly effective in the rational design and experimental realization of oxide catalysts for industry-relevant reactions.

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31P NMR and IR characterization of enantioselective olefin and arene hydrogenation catalysts containing a rhodium–chiral phosphine complex tethered on silica

Journal of Molecular Catalysis A Chemical ◽

10.1016/s1381-1169(02)00572-1 ◽

2003 ◽

Vol 195 (1-2) ◽

pp. 63-82 ◽

Cited By ~ 12

Author(s):

Keith J. Stanger ◽

Jerzy W. Wiench ◽

Marek Pruski ◽

Robert J. Angelici

Keyword(s):

31P Nmr ◽

Hydrogenation Catalysts ◽

Arene Hydrogenation ◽

Phosphine Complex

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Nanoscale Ru(0) Particles: Arene Hydrogenation Catalysts in Imidazolium Ionic Liquids

Inorganic Chemistry ◽

10.1021/ic801014f ◽

2008 ◽

Vol 47 (19) ◽

pp. 8995-9001 ◽

Cited By ~ 108

Author(s):

Martin H. G. Prechtl ◽

Morgana Scariot ◽

Jackson D. Scholten ◽

Giovanna Machado ◽

Sérgio R. Teixeira ◽

...

Keyword(s):

Ionic Liquids ◽

Hydrogenation Catalysts ◽

Imidazolium Ionic Liquids ◽

Arene Hydrogenation

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In situ characterization of Cu–Co oxides for catalytic application

Faraday Discussions ◽

10.1039/c4fd00192c ◽

2015 ◽

Vol 177 ◽

pp. 249-262 ◽

Cited By ~ 35

Author(s):

Z. Y. Tian ◽

H. Vieker ◽

P. Mountapmbeme Kouotou ◽

A. Beyer

Keyword(s):

Thermal Properties ◽

Chemical Vapor ◽

Functional Materials ◽

Catalytic Performance ◽

Structure Property ◽

Temperature Oxidation ◽

Spatially Resolved ◽

Structure Property Relationships ◽

Potential Applications

In situ emission and absorption FTIR methods were employed to characterize the spatially resolved structure of binary Co–Cu oxides for low-temperature oxidation of CO and propene. Co–Cu oxide catalysts were controllably synthesized by pulsed-spray evaporation chemical vapor deposition. XRD, FTIR, XPS, UV-vis and helium ion microscopy (HIM) were employed to characterize the as-prepared thin films in terms of structure, composition, optical and thermal properties as well as morphology. In situ emission FTIR spectroscopy indicates that Co3O4, CuCo2O4 and CuO are thermally stable at 650, 655 and 450 °C, respectively. The catalytic tests with absorption FTIR display that the involvement of Co–Cu oxides can initiate CO and C3H6 oxidation at lower temperatures. The results indicate that in situ emission and absorption FTIR are useful techniques to explore the thermal properties and catalytic performance of functional materials, allowing many potential applications in tailoring their temporally and spatially resolved structure-property relationships.

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