Questions tagged [catalysis]
This tag is appropriate for reactions, their mechanisms, their kinetics, when catalysts of any kind are involved.
310
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Choice of transition metals for catalysis in hydrogenation reactions
As is commonly known, metals Ni, Pt and Pd are used for catalysis in hydrogenation reactions. There are also coordination complexes containing Ir, Rh and Ru metals that act as catalysts for ...
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How does water interfere in ozone manufacture by increasing the production of nitric oxide?
I was just reading about ozone production and it's alleged medical uses (Gwyneth Paltrow stated that she increases her 'wellness' by blowing it up her, um, front and rear 'doors) when I came across ...
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Aromatisation of Alkanes
My textbook mentions the following reactions:
However the mechanism is not available
What is the mechanism for cyclisation and aromatisation of an n-alkane and how does the catalyst help?
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Determining volume of hydrogen gas evolved in water splitting reaction
I want to carry out a photocatalytic water spliting reaction. This reaction will generate Hydrogen and Oxygen gas in 2:1 ratio according to the following reaction -
2H2O + energy (light) → 2H2 + O2
So,...
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Estimate scaled up rate of gas phase reaction
I have measured the conversion rate of a particulate-catalyzed gas phase reaction in a reactor. That is, I have a graph of how fast $\pu{1 mol}$ of catalyst converts $\pu{1 mol}$ of reactant into $\pu{...
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Effect of catalytic NaOH on atom economy
I conducted a base catalyzed aldol condensation using NaOH. Now I'm supposed to calculate the atom economy, AE:
$$\text{AE} = \frac{{\text{MW of desired product}}}
{\sum{\text{MW of reactants}}} \...
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Do PEM Fuel Cells suffer CO poisoning at the oxidizer side?
Reading about PEM Fuel Cells, first on Wikipedia then on some other sites, I notice they talk a lot about the problem of CO poisoning. But almost always it's explicitly referred to as a problem in ...
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Why is the sp3-sp3 reductive elimination between the R1 and norbornene in the Catellani Cycle ''not favorable''?
I have recently started reading a book about C-H activation and I cannot figure out why in the Catellani reaction cycle the R1-norbornene reductive elimination side reaction which can be a major issue ...
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Do asymmetrical HER/HOR catalysts exist?
Suppose I have an electrochemical hydrogen pump (Wikipedia), whereby I have an anode and cathode, each with supported catalyst, separated by a proton exchange membrane. When I apply an appropriate ...
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Which is a better poison to the Haber's process, $\ce{CO}$ or $\ce{H2S}$? [closed]
I am studying about catalysts and their promoters and poisons and came across two of the possible poisons for Fe used during Haber's process and wanted to compare their effect on the rates of reaction....
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Why does base aspirin hydrolysis work better than acid aspirin hydrolysis? [duplicate]
Why does base aspirin hydrolysis work better than acid aspirin hydrolysis?
I conducted an experiment and found that there was greater Salicylic Acid yield for the one I added base compared to the one ...
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Titanium-free catalysts to decrease decomposition temperature of magnesium hydride
Magnesium hydride $(\ce{MgH2})$ is a metal hydride with a relatively stable structure, at least compared to other metal hydrides. Magnesium hydride splits at around 300 °C into magnesium and hydrogen. ...
user123716
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Conditions for Pd/C reduction of alkene
I am trying to do a $\ce{H2}$ reduction of cyclic alkene (otherwise simple hydrocarbon with 1 methyl group along with the chain about the weakly-strained cycle) using $\ce{Pd/C}$, the cycloalkene ...
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Is the Glaser coupling reaction possible with metal alkyne complexes?
As the Glaser coupling reaction is usually done with terminal alkynes with the hydrogen being straight, I wonder if the same reaction can occur in terminal alkynes connected to the backbone of a metal ...
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What is the inherent mechanism in carbocatalysis?
When checking non-metallic catalysis materials, one mentioned example is that of carbocatalysis; using heterogeneous carbon structure to catalyze a reaction (Not to be confused as a support surface ...
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Will hydrogen spillover be feasible on β12 borophene
Considering the fact that atomic hydrogen spillover has only been established to take place on reducible metal oxide supports, what is the possibility of spillover from palladium nanoparticles to 2D ...
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Are there any examples of chemiluminescent reaction catalyzed by Group 1/2 metals?
While researching chemiluminescent reaction that normally require enzymes but are replaced with metallic catalysts, as mentioned in this research paper: Direct and Indirect Chemiluminescence: ...
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Under what conditions does manganese dioxide lose its catalytic property?
We know that under standard conditions (room temperature and 760 mmHg air pressure) we have this reaction:
$$\ce{2H2O2(l) ->[MnO2] 2H2O(l) + O2(g)}$$
Here, manganese dioxide is behaving as a ...
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Rate equation for the decomposition of hydrogen peroxide with iron(III) chloride as catalyst [duplicate]
I am trying to determine the activation energy of the decomposition of hydrogen peroxide with iron(III) chloride added as a catalyst. To do that, I need to find the rate constant, but I am not sure ...
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Inhibitors reaction at home
For a school science project, my teacher asked me to find a reaction that can be slowed down with an inhibitor and film it at home/lab at school. He told not to use lemon on an apple or anything ...
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How to promote oxidation of copper(I) chloride to copper(II) chloride with oxygen in solution?
I recently discovered that copper(I) chloride in hydrochloric acid can react at about 80 °C with bubbled-in oxygen gas and oxidize into copper(II) chloride. I found almost no documentation on the web, ...
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When doing free radical substitution, is the free radical a catalyst?
Consider a simple free radical substitution's propagation step for $\ce{CH4}$ to $\ce{CH3Cl}$:
$$
\begin{align}
\ce{CH4 + Cl^. &-> CH3^. + HCl}\tag{R1}\\
\ce{CH3^. + Cl2 &-> CH3Cl + Cl^.}...
user104941
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Modified Arrhenius equation in the presence of a heterogeneous catalyst
Suppose we are doing heterogeneous catalysis, for example, between nitrogen and hydrogen to create ammonia in the presence of a solid catalyst, like rhuthenium. It's obvious that the gas molecules don'...
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Why is the synthesis of graphene through alkyne trimerization not viable?
I have been looking for a rationale on this as massive polycyclic aromatic hydrocarbons have been synthesized this way, and with Graphene just being an indefinite expansion of aromatic rings, this has ...
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How can a catalyst be selective if it does not change the equilibrium constants?
\begin{align}
\ce{CO(g) + 3H2(g) &->[Ni] CH4(g) + H2O(g)}\\
\ce{CO(g) + 2H2(g) &->[Cu/ZnO-Cr2O3] CH3OH(g) }\\
\ce{CO(g) + H2(g) &->[Cu] HCHO(g) }
\end{align}
As we see here, ...
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Which amines show N−N coupling reaction?
We add 1 equivalent of $\ce{KCN}$ followed by catalytic reduction via Lindlar's reagent $(\ce{H2}/\ce{Pt})$ to 4-chlorobenzyl chloride (1).
Verify whether the product (P) obtained will undergo an N−N ...
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How are Silanol groups functionalized unto mesoporous silica structures?
As described in this research paper:
Immobilization of Jacobsen type catalysts on modified silica, Jairo Cubillos , Edwing Grajales, Santiago Vásquez, Consuelo Montes de Correa, Rev. Fac. Ing. Univ. ...
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Regulator oxidizing NO to NO2
I have a regulator that is somehow oxidizing NO to NO2. Using a different regulator does not cause this same issue. I was wondering what could possible be contaminating the regulator that would ...
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Can an alloy catalyst change during a reaction?
I am studying the reaction pathway of oxygen evolution reaction (OER) on a PtNi alloy catalyst using density functional theory (DFT). What I found is that, for different intermediates, the most stable ...
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Why is the Tolman electronic parameter defined the way that it is?
I'm currently writing up a report on Hydrocyanation and I've been reading up on parameters people regularly use to justify their observations in regard to the performance of certain catalyst systems ...
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Purification of Buchwald-Hartwig amination
I am conducting a synthesis involving Buchwald-Hartwig amination. I use $\ce{Pd2(dba)3}$, $\ce{P(o-tol)3}$, and $\ce{Et3N}$ as base. In many proposed mechanisms, they often omit the precatalyst. I ...
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Decarboxylation of primary amino acids
Since primary amino acids like glycine, alanine can't be decarboxylated under oxidative conditions, what would be the best catalyst for this reaction?
I was thinking about copying decarboxylases with $...
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Advantages of p-toluenesulfonic acid over sulfuric acid in the formation of acetals
I am currently working on an undergraduate experiment to form a cyclic acetal.
We were asked to use p-toluenesulfonic acid as a catalyst rather than sulfuric acid.
This seems to be common practice ...
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Why do poisoned catalysts (Lindlar, nickel borate) result in partial hydrogenation of alkynes?
I read that alkene is more reactive than alkyne, so in hydrogenation of alkynes, it's difficult to isolate the alkenes.
But with poisoned catalysts like Lindlar's catalyst or Nickel-Boron (Ni2B), they ...
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What is the rate constant k for the reaction between potassium manganate and oxalic acid?
For my school's chemistry classes, I am investigating the kinetics of the redox reaction between $\ce{K2MnO4}$ and $\ce{C2H2O4}$. I analyzed the data using a colorimeter set to $\pu{565nm}$. ...
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What is the product when cyclohexanone reacts with morpholine?
The question asked to find the final product of the reaction between cylohexanone and morpholine. I attempted the reaction which is shown below:
I have understood the heat symbol. It simply ...
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Effect of short lived chemicals on global warming exceeding effect of carbon dioxide
From Wikipedia: Global Warming Potential
GWP values and lifetimes:
Nitrous oxide lasts about 121 years in the atmosphere, causes about 280 times as much warming over 20 years, but about 300 times as ...
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What is an example of chemical reaction that can be assisted by both an inorganic catalyst and an enzyme?
I have been researching chemical reactions of inorganic catalysts and enzymes and cannot find a chemical process where an inorganic compound can be replaced by an enzyme (or vice versa) and have the ...
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Mechanism of formaldehyde / phenol condensation
The production of bakelite using this method, but with an acid as the catalyst is simple enough; a protonation of the carbonyl oxygen, followed by an electrophilic substitution to the ring. The ...
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What is the product of reaction between 2‐cyclobutyl‐2‐isopropyl‐1,3‐dioxane and hydrogen with Raney nickel?
I have 2‐cyclobutyl‐2‐isopropyl‐1,3‐dioxane (alcohol protection) and I have to react it with $\ce{H2}$ and Raney nickel, but I don't know what the product would be.
I have seen a similar reaction ...
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What are the limits of size differences in a host–guest complex?
We learn in my chemistry course that there must be a snug fit for a host-guest complex to form. So, something like benzene (0.6 nm in diameter) can form a host-guest complex with a β-cyclodextrin host ...
user107675
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Hydrogen peroxide and potassium iodide reactions
What is the explanation for the two possible reactions of $\ce{H2O2}$ with $\ce{KI}$ in acid media (iodide-catalyzed decomposition of hydrogen peroxide or iodide oxidation by hydrogen peroxide) and ...
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A useful way to reuse non-recyclable plastics: Turn them to petrochemicals, shall we?
I read here (https://chemistry.stackexchange.com/a/34016/101483) that strongly acidic catalysts can facilitate dimerization of alkene. With catalysts on zeolite to allow only the isooctane (octane ...
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Finding rate constant from a change in pressure experiment
I measured the change in pressure for the decomposition of hydrogen peroxide in the presence of a manganese(IV) oxide catalyst at 5 different temperatures:
$$\ce{2 H2O2 (l) ->[MnO2 (s)] O2 (g) + 2 ...
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Why a catalyst is not consumed in a reaction when all steps are reversible?
It is said that a catalyst speeds up the rate of a reaction but is not consumed (assuming no side reactions take place). Suppose we have the following reaction:
$$\ce{A + B <=> C} $$
catalysed ...
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Succinic anhydride esterification won't go forward
I'm trying to react succinic anhydride with a decyl alcohol to produce mono-decyl succinate. Literature and Google searches suggest that the monoesterification should proceed without catalyst. However ...
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database for catalytic reaction mechanism
I am looking for a database containing detailed reaction mechanisms for (homogenous) catalytic reactions. Regular organic textbooks or papers generally draw some broad picture of how the mechanism may ...
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catalysts in catalytic hydrogenation
I am studying the very BASIC introduction of catalysis in general chemistry and encountered an example of a heterogeneous catalyst, which is catalytic hydrogenation of alkene into alkane using Pt/C or ...
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Frequency Factor of the Arrhenius Equation
The question came to my mind as to whether the effect of a catalyst on a reaction included the modification of the frequency factor (or pre-exponential factor) of a reaction, shown in Arrhenius' ...
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Ascorbic acid and aldehydes: Reaction and Influencing Metals
I've researched online and I've read that ascorbic acid can both promote oxidation and reduction depending on the conditions (I've read about trace metals but I've never found which metals affect its ...
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