Reactions over supported metal catalysts. VI. The effect of halogen compounds on transition metal catalysts supported on silica or pumice. Reactions of 3-methylnortricyclene

1980 ◽  
Vol 33 (10) ◽  
pp. 2261 ◽  
Author(s):  
WR Jackson ◽  
DM Nicolson
Keyword(s):  
Transition Metal ◽  
Platinum Catalysts ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Supported Metal Catalysts ◽  
Halogen Compounds ◽  
Product Distributions ◽  
Catalyst Acidity ◽  
Distribution Studies ◽  
Deuterium Distribution

The product distributions from reactions of 3-methylnortricyclene with hydrogen over palladium or platinum catalysts supported on silica or pumice vary significantly after treatment of the catalyst with small amounts of halogen-containing compounds. Evidence is presented, including deuterium distribution studies utilizing 2H N.M.R., that these changes in products are associated with intermediates which have greater sp2 character at the reacting carbon atoms and that the formation of intermediates is not simply associated with an increase in catalyst acidity.

Reactions over supported metal catalysts. V. The effects of halogen-containing compounds on transition metal catalysts supported on silica or pumice. Reactions of 1-Methylbicyclo[4,1,0]heptane

1980 ◽  
Vol 33 (10) ◽  
pp. 2255
Author(s):  
WR Jackson ◽  
DM Nicolson
Keyword(s):  
Transition Metal ◽  
Platinum Catalysts ◽  
Product Distribution ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Supported Metal Catalysts ◽  
Supported Metal

Reactions of 1-methylbicyclo[4,1,0]heptane with hydrogen over palladium and platinum catalysts supported on pumice are described. Pretreatment of these catalysts with halogen-containing compounds greatly changes the product distribution, and the mechanism of halogen influence is discussed.

Photo-induced reduction of biomass-derived 5-hydroxymethylfurfural using graphitic carbon nitride supported metal catalysts

RSC Advances ◽  
2016 ◽  
Vol 6 (104) ◽  
pp. 101968-101973 ◽  
Author(s):  
Yuanyuan Guo ◽  
Jinzhu Chen
Keyword(s):  
Transition Metal ◽  
Carbon Nitride ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Supported Metal Catalysts ◽  
Supported Metal

Photo-induced reduction of biomass-derived 5-hydroxymethylfurfural was achieved by using graphitic carbon nitride-supported transition metal catalysts.

scholarly journals Mechanochemical synthesis of graphene oxide-supported transition metal catalysts for the oxidation of isoeugenol to vanillin

2017 ◽  
Vol 13 ◽  
pp. 1439-1445 ◽  
Author(s):  
Ana Franco ◽  
Sudipta De ◽  
Alina M Balu ◽  
Araceli Garcia ◽  
Rafael Luque
Keyword(s):  
Graphene Oxide ◽  
Transition Metal ◽  
Large Scale ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Efficient Production ◽  
Scale Production ◽  
Supported Metal Catalysts ◽  
Co Catalysts ◽  
Large Scale Production

Vanillin is one of the most commonly used natural products, which can also be produced from lignin-derived feedstocks. The chemical synthesis of vanillin is well-established in large-scale production from petrochemical-based starting materials. To overcome this problem, lignin-derived monomers (such as eugenol, isoeugenol, ferulic acid etc.) have been effectively used in the past few years. However, selective and efficient production of vanillin from these feedstocks still remains an issue to replace the existing process. In this work, new transition metal-based catalysts were proposed to investigate their efficiency in vanillin production. Reduced graphene oxide supported Fe and Co catalysts showed high conversion of isoeugenol under mild reaction conditions using H2O2 as oxidizing agent. Fe catalysts were more selective as compared to Co catalysts, providing a 63% vanillin selectivity at 61% conversion in 2 h. The mechanochemical process was demonstrated as an effective approach to prepare supported metal catalysts that exhibited high activity for the production of vanillin from isoeugenol.

scholarly journals Supported Transition Metal Catalysts for Organic Fine Chemical Synthesis: A Review

2021 ◽  
Vol 33 (3) ◽  
pp. 489-498
Author(s):  
Rajib Mistri ◽  
Bidyapati Kumar
Keyword(s):  
Transition Metal ◽  
Organic Molecules ◽  
Supported Catalyst ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Supported Metal Catalysts ◽  
Heterogeneous Catalytic ◽  
Metal Support Interaction ◽  
Supported Metal

Transition metal catalysts play an important role for synthesis of industrially and laboratory important organic fine chemicals to control the selectivity, activity and stability. In this review, we focus on mainly transition metal based supported catalyst, mainly oxide supported catalyst for heterogeneous catalytic hydrogenation and oxidation of some synthetically important organic molecules. First we discuss the industrially important catalytic organic synthetic reactions. This is followed by the role of supported metal catalysts in the heterogeneous synthetic catalytic reactions with specific attention to hydrogenation and oxidation of organic molecules. The role of base metals and noble metals in monometallic and bimetallic catalysts are then discussed. Some synthetic routes for preparation of oxide supported metal catalysts are also discussed. Finally, a general discussion of the metal-support interaction (MSI) in oxide supported metal catalysts is made.

Sulfur-Mediated Reactions through Sulfonium Salts and Ylides

Synlett ◽  
2021 ◽  
Author(s):  
Pingfan Li
Keyword(s):  
Transition Metal ◽  
Rational Design ◽  
Acid Catalysis ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Bronsted Acid ◽  
Proof Of Concept ◽  
Sulfonium Salts ◽  
Brönsted Acid ◽  
Sulfonium Ylides

AbstractThis Account discusses several new reaction methods developed in our group that utilize sulfur-mediated reactions through sulfonium salts and ylides, highlighting the interplay of rational design and serendipity. Our initial goal was to convert aliphatic C–H bonds into C–C bonds site-selectively, and without the use of transition-metal catalysts. While a proof-of-concept has been achieved, this target is far from being ideally realized. The unexpected discovery of an anti-Markovnikov rearrangement and subsequent studies on difunctionalization of alkynes were much more straightforward, and eventually led to the new possibility of asymmetric N–H insertion of sulfonium ylides through Brønsted acid catalysis.1 Introduction2 Allylic/Propargylic C–H Functionalization3 Anti-Markovnikov Rearrangement4 Difunctionalization of Alkynes5 Asymmetric N–H Insertion of Sulfonium Ylides6 Conclusion

scholarly journals Facet-Dependent Reactivity of Ceria Nanoparticles Exemplified by CeO2-Based Transition Metal Catalysts: A Critical Review

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 452
Author(s):  
Michalis Konsolakis ◽  
Maria Lykaki
Keyword(s):  
Transition Metal ◽  
Co Oxidation ◽  
Critical Review ◽  
Rational Design ◽  
Metal Catalysts ◽  
Co2 Hydrogenation ◽  
Transition Metal Catalysts ◽  
Fine Tuning ◽  
Ceria Nanoparticles ◽  
Highly Active

The rational design and fabrication of highly-active and cost-efficient catalytic materials constitutes the main research pillar in catalysis field. In this context, the fine-tuning of size and shape at the nanometer scale can exert an intense impact not only on the inherent reactivity of catalyst’s counterparts but also on their interfacial interactions; it can also opening up new horizons for the development of highly active and robust materials. The present critical review, focusing mainly on our recent advances on the topic, aims to highlight the pivotal role of shape engineering in catalysis, exemplified by noble metal-free, CeO2-based transition metal catalysts (TMs/CeO2). The underlying mechanism of facet-dependent reactivity is initially discussed. The main implications of ceria nanoparticles’ shape engineering (rods, cubes, and polyhedra) in catalysis are next discussed, on the ground of some of the most pertinent heterogeneous reactions, such as CO2 hydrogenation, CO oxidation, and N2O decomposition. It is clearly revealed that shape functionalization can remarkably affect the intrinsic features and in turn the reactivity of ceria nanoparticles. More importantly, by combining ceria nanoparticles (CeO2 NPs) of specific architecture with various transition metals (e.g., Cu, Fe, Co, and Ni) remarkably active multifunctional composites can be obtained due mainly to the synergistic metalceria interactions. From the practical point of view, novel catalyst formulations with similar or even superior reactivity to that of noble metals can be obtained by co-adjusting the shape and composition of mixed oxides, such as Cu/ceria nanorods for CO oxidation and Ni/ceria nanorods for CO2 hydrogenation. The conclusions derived could provide the design principles of earth-abundant metal oxide catalysts for various real-life environmental and energy applications.

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