engineering

Nanomaterial-based catalyst

Nanomaterial-based catalyst is a engineering topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Nanomaterial-based catalyst rather than just read about it. In short: A nanomaterial-based catalyst, also known as nanocatalyst, is usually a heterogeneous catalyst based upon metal nanoparticles. Metal nanoparticles have high surface area, which can increase catalytic activity.

Key takeaways

Nanomaterial-based catalyst belongs to engineering; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Nanomaterial-based catalyst to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Nanomaterial-based catalyst from memory before moving on to harder problems.

Reference excerpt

A nanomaterial-based catalyst, also known as nanocatalyst, is usually a heterogeneous catalyst based upon metal nanoparticles. Metal nanoparticles have high surface area, which can increase catalytic activity. Nanoparticle catalysts can be easily separated and recycled. They are typically used under mild conditions to prevent decomposition or agglomeration of the nanoparticles. In many cases they are supported on substrates, sometimes they are not.

Functionalized nanoparticles Functionalized metal nanoparticles are more stable toward solvents compared to non-functionalized metal nanoparticles. In liquids, the metal nanoparticles can be affected by van der Waals force. Particle aggregation can sometimes decrease catalytic activity by lowering the surface area. Nanoparticles can also be functionalized with polymers or oligomers to sterically stabilize the nanoparticles by providing a protective layer that prevents the nanoparticles from interacting with each other. Alloys of two metals, called bimetallic nanoparticles, are used to create synergistic effects on catalysis between the two metals.

Potential applications

Dehalogenation and hydrogenation Nanoparticle catalysts are active for the hydrogenolysis of C-Cl bonds such as polychlorinated biphenyls. Another reaction is hydrogenation of halogenated aromatic amines is also important for the synthesis of herbicides and pesticides as well as diesel fuel. In organic chemistry, hydrogenation of a C-Cl bond with deuterium is used to selectively label the aromatic ring for use in experiments dealing with the kinetic isotope effect. Buil et al. created rhodium complexes that generated rhodium nanoparticles. These nanoparticles catalyzed the dehalogenation of aromatic compounds as well as the hydrogenation of benzene to cyclohexane. Polymer-stabilized nanoparticles can also be used for the hydrogenation of cinnamaldehyde and citronellal. Yu et al. found that the ruthenium nanocatalysts are more selective in the hydrogenation of citronellal compared to the traditional catalysts used.

Hydrosilylation reactions

The Reduction of gold, cobalt, nickel, palladium, or platinum organometallic complexes with silanes produces metal nanoparticle that catalyze the hydrosilylation reaction. BINAP-functionalized palladium nanoparticles and gold nanoparticles have been used for the hydrosilylaytion of styrene under mild conditions; they were found to be more catalytically active and more stable than non-nanoparticle Pd-BINAP complexes. The reaction may also be catalyzed by a nanoparticle that consists of two metals.

Organic redox reactions

An oxidation reaction to form adipic acid is shown in figure 3 and it can be catalyzed by cobalt nanoparticles. This is used in an industrial scale to produce the nylon 6,6 polymer. Other examples of oxidation reactions that are catalyzed by metallic nanoparticles include the oxidation of cyclooctane, the oxidation of ethene, and glucose oxidation.

C-C coupling reactions

Metallic nanoparticles can catalyze C–C coupling reactions such as the hydroformylation of olefins, the synthesis of vitamin E and the Heck coupling and Suzuki coupling reactions. Palladium nanoparticles were found to efficiently catalyze Heck coupling reactions. It was found that increased electronegativity of the ligands on the palladium nanoparticles increased their catalytic activity. The compound Pd2(dba)3 is a source of Pd(0), which is the catalytically active source of palladium used for many reactions, including cross coupling reactions. Pd2(dba)3 was thought to be a homogeneous catalytic precursor, but recent articles suggest that palladium nanoparticles are formed, making it a heterogeneous catalytic precursor.

Alternative fuels Iron oxide and cobalt nanoparticles can be loaded onto various surface active materials like alumina to convert gases such as carbon monoxide and hydrogen into liquid hydrocarbon fuels using the Fischer-Tropsch process. Much research on nanomaterial-based catalysts has to do with maximizing the effectiveness of the catalyst coating in fuel cells. Platinum is currently the most common catalyst for this application, however, it is expensive and rare, so a lot of research has been going into maximizing the catalytic properties of other metals by shrinking them to nanoparticles in the hope that someday they will be an efficient and economic alternative to platinum. Gold nanoparticles also exhibit catalytic properties, despite the fact that bulk gold is unreactive. Yttrium stabilized zirconium nanoparticles were found to increase the efficiency and reliability of a solid oxide fuel cell. Nanomaterial ruthenium/platinum catalysts could potentially be used to catalyze the purification of hydrogen for hydrogen storage. Palladium nanoparticles can be functionalized with organometallic ligands to catalyze the oxidation of CO and NO to control air pollution in the environment. Carbon nanotube supported catalysts can be used as a cathode catalytic support for fuel cells and metal nanoparticles have been used to catalyze the growth of carbon nanotubes. Platinum-cobalt bimetallic nanoparticles combined with carbon nanotubes are promising candidates for direct methanol fuel cells since they produce a higher stable current electrode.

Medicine In magnetic chemistry, nanoparticles can be used for catalyst support for medicinal use.

Nanozymes Besides conventional catalysis, nanomaterials have been explored for mimicking natural enzymes. The nanomaterials with enzyme mimicking activities are termed as nanozymes. Many nanomaterials have been used to mimic varieties of natural enzymes, such as oxidase, peroxidase, catalase, SOD, nuclease, etc. The nanozymes have found wide applications in many areas, from biosensing and bioimaging to therapeutics and water treatment.

Nanostructures for electrocatalysis Nanocatalysts are of wide interest in fuel cells and electrolyzers, where the catalyst strongly affects efficiency.

Nanoporous surfaces

In fuel cells, nanoporous materials are widely used to make cathodes. Porous nanoparticles of platinum have good activity in nanocatalysis but are less stable and their lifetime is short.

Nanoparticles

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Nanomaterial-based catalyst

Start with the simplest possible case. Write down what Nanomaterial-based catalyst claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In engineering, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Nanomaterial-based catalyst before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Nanomaterial-based catalyst ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Nanomaterial-based catalyst

In research: Nanomaterial-based catalyst appears in engineering research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Nanomaterial-based catalyst in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Nanomaterial-based catalyst is common in secondary-school and first-year university syllabi. It links to neighbouring topics Catalysis, Nanomaterials, so understanding it makes those chapters shorter.
In everyday life: Look for Nanomaterial-based catalyst outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Nanomaterial-based catalyst in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Nanomaterial-based catalyst means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Nanomaterial-based catalyst out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Nanomaterial-based catalyst in simple terms?

Why does Nanomaterial-based catalyst matter?

Because it connects several engineering ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Nanomaterial-based catalyst?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Nanomaterial-based catalyst.