A catalyst is a substance that increases the rate of a reaction without modifying the overall standard Gibbs energy change in the reaction; the process is called catalysis. This tag is appropriate for reactions, their mechanisms, their kinetics, when catalysts of any kind are involved.

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why platinum/palladium are such a good catalyst?

Platinum and palladium are great catalysts. At the same time, other metals of the same family are not. What are the atomic level reasons for this?
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674 views

Why is more of a catalyst added, when it is not consumed?

… catalysis, the acceleration of chemical reactions by substances not consumed in the reactions themselves—substances known as catalysts. (Source) Now as I’ve understood, to keep a reaction ...
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56 views

Effect of Catalysis on Reaction Rate in elementary Reaction

I understand that there are many different catalytic mechanisms that suggest different ways of accounting for the effect of a catalyst on reaction rate. My question is: Given a termolecular ...
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80 views

Does a catalyst increase atom economy?

Somebody I know insists that the use of a catalyst increases the atom economy. They did chemistry at school, and were told that a catalyst increases the atom economy. He pointed me to several past ...
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45 views

The Propinquity Effect

I am currently in the process of studying enzyme catalysis and am struggling to get to grips with this concept. As far as I understand, the propinquity effect allows substrates to bind with enzymes in ...
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60 views

Grubbs & Wittig reactions and Woodward-Hoffmann rules

The mechanism of the olefine metathesis using Grubbs' catalyst consists of [2+2] cycloadditions and reverse cycloadditions. The Wittig reaction, too. How are they in accordance with the ...
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Basis set in the computational software “Gaussian-03” for studying adsorption of a hydrogen atom on a carbon paste electrode dropcasted with Pt-CNT

What is the basis set in the computational software "Gaussian-03" that can be used to study the interaction of $\ce{H}$-atom with $\ce{Pt-CNT}$ dropcasted electrode? How can we study the energy ...
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35 views

jury-rigging an automotive catalytic converter for use in the Ostwald Process?

Would it be feasible to jury-rig an automotive catalytic converter for use in the Ostwald Process for the production of Nitric Acid? Given reasonable safety precautions, would it be safe enough to be ...
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378 views

When an enzyme is diluted with water, what is slowing down the rate of reaction?

I'm specifically talking about the decomposition of hydrogen peroxide by bovine catalase. The number of catalase molecule obviously doesn't change, so there's the same number of catalase molecule ...
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31 views

compression set of tin catalyzed silicone better than platinum?

Platinum silicone is more dimensionaly stable, it shrinks less when it cures. However, i just need silicone which has good compression set (small change by compression), and perhaps, once they are ...
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27 views

Electrode for methanol

Could you advice an electrode for electrophoretic deposition in methanol which won't spoil methanol and also wont be spoiled by methanol. I googled a bit and found that 1 copper, platinum and gold are ...
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57 views

Lewis Acid Catalysts [closed]

I am studying for the International Chemistry Olympiad and some of questions involve synthesis of complicated organic compounds and i have no idea how to do them. The setting of the questions is ...
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71 views

How are catalysts discovered for a particular reaction?

I want to understand how are catalysts discovered for a particular chemical reactions say for example $\ce{Fe,~Mo}$ for Haber's Process reaction of $\ce{N2}$ & $\ce{H2}$. Reactions as examples ...
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A misunderstanding about the energy profile of reactions with a catalyst involved

All of us are aware of the importance of the catalysts in bio-chemistry. For a high school learner like me, catalysts ,and therefore, enzymes play a bridge-like role that connect high school bio to ...
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94 views

How does a Catalytic Poison reduce a catalysts activity

How does A catalytic poison reduce the activity of a catalyst, such as palladium used in hydrogenation of alkenes or any other such catalyst.
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Does product induced poisoning qualify as a rate limiting step?

I have a question about whether a particular situation qualifies as a rate limiting step. I have a catalyst that under normal conditions gets poisoned when products accumulate on the catalyst surface. ...
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133 views

What is a sacrificial agent?

I came across this reading a journal article. Here I have the context: Here we report for the first time the synthesis of $\ce{TiO2}$ NPs on a layered $\ce{MoS2}$/graphene (MG) hybrid for use in ...
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266 views

Differences between Urushibara nickel and Raney nickel

The Wikipedia article about Urushibara nickel catalyst is rather short and vague. What is the mechanism for its preparation, and furthermore, in what sense does it differ from Raney nickel (i.e. when ...
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269 views

What are the specific disadvantages of using a bio-catalyst (called Lipolase) in the synthesis of the drug pregabalin?

I am studying the synthesis of a drug pregabalin, for which both chemical and bio-catalysts are used. Using a biocatalyst is way better than chemical route, as explained here. In fact, The invention ...
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39 views

What is the type of dependence of the rate of reaction on the amount of catalyst?

I have performed an experiment where I had some test tubes with the reagents and different amounts of catalyst. I started the reactions and measured the time they took. Then I calculated the rate of ...
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117 views

Why it is not yet possible to produce ethanol selectively in the Fischer Tropsch reaction?

The Fischer Tropsch reaction between $\ce{CO}$ and $\ce{H2}$ has the potential to give a wide range of products. However by judicious choice of catalytic metal it is possible to produce $\ce{CH4}$, ...
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298 views

How does salt and water promote corrosion?

I was always wondering why iron only rusts when it gets wet. I know that for example aluminium oxidises on its own on regular basis. I also heard many complains that salt used to remove snow from ...
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413 views

Is there a catalyst that will reduce an alcohol to an alkane?

There are many reduction methods of going from an alcohol to an alkane: http://www.transtutors.com/chemistry-homework-help/hydrocarbons/reduction-of-alcohols.aspx And there are catalytic methods of ...
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76 views

Photoelectrochemical (PEC) water splitting

I'm starting to prepare for my research project on photoelectrochemical (PEC) splitting of water into H and O using (F doped) titanium dioxide as the photoanode. I've been unsuccessfully searching in ...
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819 views

Why do we need acid when making acetone peroxide?

Acetone peroxide is a very dangerous explosive, easily detonated by mild heating, friction or shock. It appears in the form of small white crystals. This compound forms from the mixture of hydrogen ...
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209 views

Which has higher rate of hydrogenation- methyl propene or trans-2-butene?

I know that cis-2-butene has a higher rate of hydrogenation than both of these due to steric reasons, but here both of these compounds have same steric hindrance. So, when they come in contact with ...
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Hydrogenation stereochemistry-Pd,Pt, Ni catalysts

When my textbook talks about hydrogenation using Pt, Pd or Ni heterogeneous catalysts, it never mentions if it is anti or syn addition. It simply jumps on to say that for alkynes, NiB2 (P-2) catalysts ...
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Catalytic iodine in synthesis of phosphonium salts

From Clayden et al. However, iodine is expensive and a way round that problem is to use a catalytic amount of iodide. The next phosphonium salt is formed slowly from benzyl bromide but the ...
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Difference between nickel catalyst and Raney nickel catalyst

Many times i have seen the catalyst as Raney nickel instead of nickel catalyst. I think Raney is a name of chemist who discovered Raney nickel catalyst.I think Raney nickel catalyst and nickel ...
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55 views

How can one come to know how a catalyst affects a reaction when the reaction and the catalyst is known

How can I come to know how a catalyst affects a reaction when the reaction and the catalyst used is known. I searched the internet for an answer but could not find one.
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How can water catalyse a reaction between iodine and aluminium?

A few drops of water can initiate a reaction between iodine and aluminium. https://www.youtube.com/watch?v=SKSU72-1ERc How can this happen, since iodine is only slightly soluble in water?
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104 views

Decreasing rate of reaction between $\ce{I2(s)}$ and $\ce{H2(g)}$?

Which change will decrease the rate of the reaction between $\ce{I2(s)}$ and $\ce{H2(g)}$? (A) Increasing the partial pressure of $\ce{H2(g)}$ (B) Adding the $\ce{I2(s)}$ as one piece ...
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59 views

How to speed up flash powder flaming reaction

Do you have an idea how can be flaming of flash powder (probably $\ce{KClO_4} $ (60%) + $\ce{Al}$ (40%) ) can be speeded up? Of course we consider the pure oxygen-in-air conditions. So how? With some ...
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229 views

Why platinum used as a catalyst in fuel cell electrodes (and elsewhere)?

I have rather basic knowledge of chemistry (at the level of a first year college class). But maybe somebody can still clarify with some simple words: What makes platinum a good catalyst for the ...
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64 views

Ozone catalysis

I know that catalysts don't change chemical equilibrium because they accelerate both the reactions in the same way. I can't understand why CFC catalysts accelerate ozone destruction but not ozone ...
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1k views

Reaction intermediates of MnO2 catalyzed H2O2 decomposition reaction

Manganese dioxide catalyzes the decomposition of hydrogen peroxide to water and oxygen gas. But what are the intermediates in this catalyzed reaction?
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What is 'coprecipitated (Ni,Fe)S'?

I am writing an essay on the origin of life and I was reading an article on hydrothermal vents. (Peptides by Activation of Amino Acids with CO on (Ni,Fe)S Surfaces: Implications for the Origin of ...
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Analytical solution to first-order rate laws

Does anyone know the analytical solutions to the following rate laws: 1) $\frac{\mathrm{d}\rho_\text{W}}{\mathrm{d}t} = -\rho_\text{W} \cdot (K_1+K_2+K_3)$ 2) ...
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29 views

Reduction by thermionic electrons

Certain reduction reactions require electrons as reducing agents. Is the overlapping of orbitals is necessary for electron transfer? I mean if a element $\ce{X}$ is heated and it gives out thermionic ...
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865 views

How does sulfuric acid catalyze the reaction of potassium chlorate and sucrose?

Part of the total reaction is mentioned here: http://chemistry.about.com/od/demonstrationsexperiments/ht/instantfire.htm $\ce{2KClO3(s)} + \text{heat} \rightarrow 2\ce{KCl(s)} + 3\ce{O2(g)}$ The ...
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384 views

How does Palladium dissociate H₂ so easily?

If I understand correctly, $\ce{H2}$ in the presence of $\ce{Pd}$ readily dissociates as it dissolves into the metal. With the dissociation energy for the $\ce{H—H}$ bond being so large, how is this ...
14
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333 views

What is the chemistry behind this “petrol from air” technology?

A recent news report in the UK claimed a breakthrough in making a petrol equivalent from carbon dioxide and water: A small British company has produced the first "petrol from air" using a ...
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89 views

How does the work that won the 2012 Sustainable Chemistry Award contribute to sustainable chemistry?

I'm seeking a lay explanation for how the work of Dr Marc Taillefer that won the 2012 European Sustainable Chemistry Award, contributes to sustainable chemistry. From the press release, Dr. Taillefer ...
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257 views

Energy-efficiency aside, what are the chemical constraints on CO₂ capture and methanation?

Synthesising $\ce {CH4}$ from air and water (in a non-biological process) has been proposed as one form of energy storage. What are the chemical constraints at play here? That is to say, what sort of ...