Supported Catalysts Weiting Yu,† Marc D. Porosoff,† and Jingguang G. Chen*,†,‡,§ †Catalysis Center for Energy Innovation, Department of Chemical and Bimolecular Engineering, University of Delaware, Newark, Delaware 19716, United States ‡Department of Chemical Engineering, Columbia University, New York, New York 10027, United States Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973, United States

Review of Pt-based bimetallic catalysis: from model surfaces to supported catalysts.

Concerns about the depletion of fossil fuel reserves, the impact of anthropogenic CO2 emissions, and increasing energy demands have encouraged the exploration of new catalytic procedures for converting cellulosic biomass into valuable platform chemicals and renewable fuel components. The development of these sustainable catalytic transformations could potentially provide a long-term solution to the industrial dependence on fossil carbon, requiring in 2025 production of up to 30% of raw materials for the chemical industry from renewable resources. With an abundance of approximately 720 billion tonnes, that is, 40% of the annual net yield of photosynthesis, cellulose is the world’s largest organic raw material resource. Whereas nature renews 40 billion tonnes every year, no more than 200 million tonnes of this nonedible biomass are processed, mainly as a raw material for paper and packaging industry. The blueprints of the “new” cellulose chemistry are based on some key elements, namely controlled depolymerization of the biopolymer and catalytic cascade reactions (e.g. , hydrogenation, hydrogenolysis, oxidation), which, when put together, yield a pool of molecules that can be used for the synthesis of industrial intermediates and fine chemicals. One of the methods for chemical degradation of cellulose is the acid-catalyzed hydrolytic cleavage into its glucose monomers, which are, for example, of high interest for further fermentation into bioethanol. 6] An excellent review on cellulose hydrolysis as an entry point into biorefinery schemes has recently been published by Rinaldi and Sch th. Also as an introduction, we recommend more general reviews on the challenges and issues involved in the catalytic processing of biomass. In this Minireview, we focus on the impressive scope of recent catalytic advances in the conversion of cellulose over solid acid and multifunctional catalysts, the direct conversion into furan-based or valeric biofuels, liquid alkenes, alkyl glycosides, and cellulose dissolution and processing in ionic liquids. Particular emphasis will be on concepts known from heterogeneous and multistep catalysis. Before the different catalytic strategies are discussed, structural aspects as well as specific chemical and physical properties of cellulose will be briefly addressed, as this knowledge is a prerequisite for the rational design of new catalytic transformations.

Recent Advances in the Catalytic Conversion of Cellulose

Microreactor technology and continuous flow processing in general are key features in making organic synthesis both more economical and environmentally friendly. Heterogeneous catalytic hydrogenation reactions under continuous flow conditions offer significant benefits compared to batch processes which are related to the unique gas-liquid-solid triphasic reaction conditions present in these transformations. In this review article recent developments in continuous flow heterogeneous catalytic hydrogenation reactions using molecular hydrogen are summarized. Available flow hydrogenation techniques, reactors, commonly used catalysts and examples of synthetic applications with an emphasis on laboratory-scale flow hydrogenation reactions are presented.

Heterogeneous Catalytic Hydrogenation Reactions in Continuous‐Flow Reactors

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Are alkyne reductions chemo-, regio-, and stereoselective enough to provide pure (Z)-olefins in polyfunctionalized bioactive molecules?

The catalytic hydrogenation of carboxylic acid derivatives represents an atom-efficient and clean reduction methodology in organic chemistry. More specifically, the selective hydrogenation of nitriles offers the possibility for a green synthesis of valuable primary amines. So far, this transformation lacks of useful, broadly applicable non-noble metal-based catalyst systems. In the present study, we describe a molecular-defined iron complex, which allows for the hydrogenation of aryl, alkyl, heterocyclic nitriles and dinitriles. By using an iron PNP pincer complex, we achieve very good functional group tolerance. Ester, ether, acetamido as well as amino substituents are not reduced in the presence of nitriles. Moreover, nitriles including an α,β-unsaturated double bond and halogenated derivatives are well tolerated in this reaction. Notably, our complex constitutes the first example of an homogeneous catalyst, which permits the selective hydrogenation of industrially important adipodinitrile to 1,6-hexamethylenediamine.

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Mild and selective hydrogenation of aromatic and aliphatic (di)nitriles with a well-defined iron pincer complex.

Preface. Hydrogenation Catalysts. Reactors and Reaction Conditions. Hydrogenation of Alkenes. Hydrogenation of Alkynes. Hydrogenation of Aldehydes and Ketones. Preparation of Amines by Reductive Alkylation. Hydrogenation of Nitriles. Hydrogenation of Imines, Oximes, and Related Compounds. Hydrogenation of Nitro, Nitroso, and Related Compounds. Hydrogenation of Carboxylic Acids, Esters, and Related Compounds. Hydrogenation of Aromatic Compounds. Hydrogenation of Heterocyclic Aromatic Compounds. Hydrogenolysis. General Bibliography. Author Index. Subject Index.

重夫西村

Papers

Handbook of heterogeneous catalytic hydrogenation for organic synthesis

重夫 西村

Papers

Handbook of heterogeneous catalytic hydrogenation for organic synthesis

重夫西村