Hydrogenation Reactions
Hydrogenation Reactions - Related Videos
06:06
Hydrogenation
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2023
Source: Vy M. Dong and Zhiwei Chen, Department of Chemistry, University of California, Irvine, CA This experiment will demonstrate the hydrogenation of chalcone as an example of an alkene hydrogenation reaction (Figure 1). In this experiment, palladium on carbon (Pd/C) will be used as a heterogeneous catalyst for the process. A balloon will be used to supply the hydrogen atmosphere. Figure 1: Diagram showing the hydrogenation of chalcone to 3-phenylpropiophenone.
06:32
A Simple, Low-cost, and Robust System to Measure the Volume of Hydrogen Evolved by Chemical Reactions with Aqueous Solutions
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Cited by 15 •
2016
The study of methods to generate on-demand hydrogen for fuel cells continues to grow in importance. However, systems to measure hydrogen evolution from the reaction of chemicals with water can be complicated and expensive. This article details a simple, low-cost, and robust method to measure the evolution of hydrogen gas.
14:11
Quantification of Hydrogen Concentrations in Surface and Interface Layers and Bulk Materials through Depth Profiling with Nuclear Reaction Analysis
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Cited by 21 •
2016
We illustrate the application of 1H(15N,αγ)12C resonant nuclear reaction analysis (NRA) to quantitatively evaluate the density of hydrogen atoms on the surface, in the volume, and at an interfacial layer of solid materials. The near-surface hydrogen depth profiling of a Pd(110) single crystal and of SiO2/Si(100) stacks is described.
08:56
Catalytic Reactor: Hydrogenation of Ethylene
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2023
Source: Kerry M. Dooley and Michael G. Benton, Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA The hydrogenation of ethylene (C2H4) to ethane (C2H6) has often been studied as a model reduction reaction in characterizing new metal catalysts.1-2 While supported nickel is not the most active metal catalyst for this reaction, it is active enough that reaction can take place at < 200°C. The reaction typically involves adsorbed, dissociated hydrogen (H2) reacting...
01:19
Chemical Reactions
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2019
A chemical reaction is a process by which the bonds in the atoms of substances are rearranged to generate new substances. Matter cannot be created or destroyed in a chemical reaction—the same type and number of atoms that make up the reactants are still present in the products. Merely, the rearrangement of chemical bonds produces new compounds. Chemical Reactions Rearrange Atoms into New Substances A chemical reaction takes starting materials—the reactants—and changes them into different...
FAQs
Metal catalysts such as palladium, platinum, and nickel provide a pathway for hydrogen activation by weakening the H–H bond. This makes hydrogen atoms available to add across carbon–carbon double or triple bonds in the reacting molecule. The catalyst therefore helps the transformation occur while influencing which product forms.
Selectivity depends on both catalyst choice and reaction conditions. These factors can determine whether an unsaturated starting material becomes partially or fully hydrogenated, and they can influence product composition. In practice, controlling these variables allows chemists to favor a desired molecular structure rather than treating hydrogen addition as an all-or-nothing transformation. This control matters in synthesis and industrial processing.
Partial and full hydrogenation differ in how far the substrate’s unsaturation is reduced. Reaction conditions and catalyst selection can steer the product toward a partially hydrogenated compound or a more saturated one. This distinction is important when the target structure requires controlled reactivity, a specific composition, or a useful intermediate for later synthetic steps.
A typical procedure combines the unsaturated compound with molecular hydrogen in the presence of a metal catalyst such as palladium, platinum, or nickel. The catalyst activates hydrogen, enabling its atoms to add at the molecule’s carbon–carbon multiple bond. Chemists then assess whether the resulting material is partially or fully hydrogenated, based on the intended product.
Industrial use illustrates how product control affects large-scale chemistry. Hydrogenation helps process vegetable oils and refine petrochemical feedstocks, where changing the saturation of molecular components can produce materials with desired compositions. The same underlying chemistry also supports organic synthesis, but industrial applications place particular importance on catalyst selection and conditions because these variables influence the mixture obtained.
When chemists use hydrogenation in organic synthesis, they can deliberately modify a molecule’s structure and reactivity rather than merely prepare a more saturated product. The transformation can generate valuable intermediates for subsequent chemical work. Choosing suitable conditions helps align the product composition with the synthetic objective, especially when partial and complete hydrogenation would lead to different outcomes.