Questions tagged [catalysis]

This tag is appropriate for reactions, their mechanisms, their kinetics, when catalysts of any kind are involved.

Filter by
Sorted by
Tagged with
0
votes
0answers
16 views

Doubt's regarding inputting surface reaction for Chemkin Pro

I want to simulate the reaction of a mixture of ethanol and Hydrogen Peroxide on $\ce{Pt}$ using Chemkin Pro. I want to create a surface input files which will include surface reaction mechanism of ...
1
vote
0answers
34 views

Why is copper(II) used a catalyst here instead of as an intermediate?

Photochromic glass, used for sunglasses darkens when exposed to bright light and becomes more transparent again when the light is less bright. The depth of color of the glass is related to the ...
0
votes
0answers
27 views

Catalysts and activation energy

Do catalysts increase rate of reaction only by decreasing activation energy? Or can they affect the Arrhenius factor or reaction orders? Like if one catalyst is more effective at increasing rate of ...
0
votes
1answer
32 views

Why am I getting higher conversion values of isopropanol dehydration over a zeolite catalyst then n-propanol dehydration?

The two process are run separetly but under the same condition, same activation of the catalyst, same reaction temperature, same flow. The initial conversion of n-propanol is ~50% and isopropanol ~70%....
4
votes
1answer
57 views

Stubborn CuAAC reaction as derivatization for ESI-MS

Problem description I have a substance that is extremely non-polar and therefore does not ionize in the ESI source, which makes it impossible to quantify small amounts. The substance contains only two ...
-3
votes
1answer
45 views

What is the opposite of a catalyst and examples? [duplicate]

I remember a while ago I heard of something that slowed reactions and was effectively the opposite of a catalyst. What is this called? Also would appreciate examples and an explanation of their uses ...
1
vote
0answers
66 views

What are the most potent hydrogen peroxide decomposition catalysts available to an amateur? [closed]

Some months ago I was playing with $60\,\%$ $\ce{H2O2}$ and unknowingly I used a silver spoon to transfer the liquid from a container, and the peroxide immediately started bubbling (it did look and ...
3
votes
1answer
77 views

The dissociation of hydrogen on UO2 and PuO2 surfaces: Homolytic or heterolytic?

I have seen that $\ce{H2}$ can dissociate on a metal-oxide surface by two methods: Heterolytically, forming a proton-$\ce{O}$ bond ($\ce{OH}$ group) and a hydride-metal bond ($\ce{M-H}$) on a metal-...
3
votes
2answers
34 views

Oxidation to allylic alcohols without stoichiometric metal reagents

Common methods of oxidation of alkenes to allylic alcohols in one step usually use stoichiometric metal oxidants, e.g., sodium dichromate. Without using this type of reagent, are the other methods ...
2
votes
0answers
49 views

Can a catalyst appear in the rate equation? [duplicate]

According to Wikipedia: Chemical reactions occur faster in the presence of a catalyst because the catalyst provides an alternative reaction pathway with a lower activation energy than the non-...
2
votes
1answer
35 views

Nickel salts from hypochlorites

(JUST A HEADS UP I’m 15 years old and new to chemistry) So I was recently looking around the house looking for products that I can extract chemicals from and I found a bottle of cleaning Vinegar ( 5% ...
0
votes
0answers
15 views

catalytic activity of Pd and Pt

what phenomenon takes place during catalytic activity of Pd and Pt during hydrogenation ? in some books it is given as absorption,in others adsorption .some say that it is occlusion . please help me
5
votes
1answer
121 views

Proposed mechanism for the catalyzed oxidation of CO by O3: Are NO and NO2 catalysts or intermediates?

The steps below represent a proposed mechanism for the catalyzed oxidation of $\ce{CO}$ by $\ce{O3}$: $$\begin{align} &\text{Step 1: } & \ce{NO2(g) + CO(g) &-> NO(g) + CO2(g)} \\ &...
0
votes
1answer
60 views

What is heterogeneous catalysis in gas phase?

Give examples of heterogeneous catalysis (i) in gas phase and (ii) in liquid phase. Now, I came to know that heterogeneous catalysis involves different phases between the catalyst used and the ...
0
votes
0answers
39 views

Reaction order of a reaction with catalyst

I am given the following $\ce{H2O2 -> H2O + 1/2 O2}$ (catalysed by $\ce{KI}$) There are two solutions. $[\ce{H2O2}]$ is the same in both solutions but $[\ce{I-}]$ is $\pu{0.01M}$ and $\pu{0.005M}$,...
4
votes
1answer
46 views

What is the rate expression for decomposition of $\ce{H2O2}$ in the presence of a catalyst?

What is the rate expression for decomposition of $\ce{H2O2}$ in the presence of a catalyst? As far as I know for catalase, it is like this: $$\ce{Rate = k[H2O2][Catalase]}$$ I don't know what it is ...
0
votes
2answers
95 views

Nitrocellulose (flash paper) synthesis without Sulfuric Acid?

According to the Wikipedia page on Nitrocellulose: The process uses nitric acid to convert cellulose into cellulose nitrate and water: $$\ce{3HNO3 + C6H10O5 ->[H2SO4] C6H7(NO2)3O5 + 3H2O}$$ ...
-6
votes
1answer
56 views

what catalyst to use for the reaction between AgNO3 and NaCl? [closed]

What is the best catalyst to use for the reaction between AgNO3 and NaCl that would result in a change in activation of energy so therefore more precipitate formed. Please give me the ways I can ...
0
votes
0answers
20 views

Efficiency of H production from FeOOH catalyst?

Research has recently found that FeOOH is 25 times better at hydrogen production than titanium dioxide. Today, a new electrolysis plant delivers energy efficiency of around 80%. Is 25x the Honda-...
0
votes
1answer
52 views

Hydrogen peroxide / sodium or potassium permanganate: reaction type

I have some people on youtube stating the steam generating reaction of $$\ce{3H2O2 + 2KMnO4 → 3O2 + 2MnO2 + 2KOH + 2H2O}$$ is catalytic, from where I'm sitting it is purely stoichiometric. Can ...
4
votes
0answers
34 views

Curtin-Hammett principle to evaluate alkene insertion

Given an unsymmetrical alkene in a simple non-stereoselective catalytic hydrogenation reaction. If one would want to investigate the nuances in the catalytic cycle of a dihydride complex leading to ...
6
votes
1answer
65 views

How can subtilisin still function without its catalytic triad?

I read chapter 9 in the book Biochemistry (5th edition), by Berg, Tymoczko, and Stryer (provided in the NCBI site here). It describes the mechanism of action of the chymotrypsin enzyme. The catalysis ...
1
vote
1answer
84 views

What is the “mechanism” of the decomposition of hydrogen peroxide?

In my classwork on the decomposition reaction of hydrogen peroxide by catalase, I wrote the following equation: $$\ce{2H2O2 -> 2H2O + O2}$$ However, my teacher said that I should go further in ...
4
votes
0answers
82 views

What is it that makes this noncontact catalytic system unique in 2020?

Phys.org's Accelerating chemical reactions without direct contact with a catalyst discusses the new Science Advances paper Noncontact catalysis: Initiation of selective ethylbenzene oxidation by Au ...
0
votes
1answer
44 views

Is there any chemical that can catalyze “reverse combustion?” [closed]

I am trying to build a machine that converts carbon dioxide and water into gasoline (i.e. octane). Because the energy needs are so large, is there any catalyst chemical that can cause "reverse ...
0
votes
1answer
87 views

How to precipitate Chloroplatinic acid? [closed]

For the precipitation reaction, I have to react $\ce{H2PtCl6}$ with $\ce{(NH4)2CO3}$ while maintaining the $\ce{pH}$ in the range of 7-8 at 60 °C. But the problem is Chloroplatinic acid is not ...
3
votes
1answer
193 views

Specific reduction of certain functional groups

Consider the compound $\ce{Alkyl-(4 oxocyclopent-2-ene)carboxylate (A)}$. For example consider- Now consider the operations: $\ce{1. (A) + (i)BH3/THF (ii) H+}$ $\ce{2. (A) + H2/Pt}$ ...
0
votes
2answers
94 views

Determining a molecular formula of the catalyst for polymerisation of butadiene

I've got the following question in a workbook which I need to solve: A $\pu{50 g}$ sample of an experimental catalyst used in the polymerisation of butadiene is made up of $\pu{11.65 g}$ of $\ce{Co}...
-1
votes
2answers
131 views

What is the rate equation of decomposition of H2O2 with catalysts?

What is the rate equation of this reaction with the presence of catalysts $\ce{MnO2}$, $\ce{PbO2}$ and $\ce{Fe2O3}$? (asking for each of them, separately, not altogether) $$\ce{2H2O2 -> 2H2O + O2}$...
1
vote
1answer
116 views

Triphenylphosphine (PPh3) vs. 1,2-bis(diphenylphosphino)ethane (dppe) ligand?

What about $\ce{NiCl2(dppe)}$ makes it a more efficient catalyst for Suzuki cross-coupling as opposed to $\ce{NiCl2(PPh3)2}$ or $\ce{NiCl2(PCy3)2}$? How does the dppe ligand increase the reactivity of ...
1
vote
0answers
38 views

Source of highly nucleophilic iodide [closed]

What is be the best commercially available source of highly nucleophilic iodide in non-polar solvent? Solvents used are cyclohexane, benzene, chlorobenzene. I can get ahold of bromide quaternary ...
3
votes
0answers
55 views

Why is NOₓ conversion low at fuel rich conditions in a three-way catalytic converter?

$$ \begin{align} &\text{Oxidation:} &\quad \ce{2 CO + O2 &-> 2 CO2}\\ & & \ce{``HC" + O2 &-> CO2 + H2O}\\ & & & \\ &\text{Reduction:} &\quad \ce{2 CO +...
0
votes
1answer
40 views

Why should we be interested in catalyst for electrolysis?

I've been reading papers on Phosphided metals (CoP, NiP, FeP) as a catalyst for electrolysis. They increase the current density of the cell for a voltage. If it still requires 39.4 kilowatt-hours ...
1
vote
0answers
35 views

Are there any chemical pathways or catalysts that could produce electricity from fossil fuels without combustion?

While fossil fuels are dense in energy, I have known only one way to retrieve energy from them, namely, to burn them. I wish we could have a way to get energy from them without combustion. Is there ...
0
votes
0answers
46 views

Why Does Adding Catalyst Slow Down My Reaction?

I currently did a lab where I was meant to identify factors that increase the rate of the reaction. I reacted Glucose with Potassium Permanganate and used Sulfuric Acid as a catalyst. But in my ...
3
votes
1answer
77 views

CuSO4 in SO2/SO3 gas sampling in Sulphuric Acid Production

What role does $\ce{CuSO4}$ has in the gas sampling of an $\ce{SO2/SO3}$ gas mix in a catalytic converter for sulphuric acid production? To give you a little context: We take gas samples from the ...
3
votes
1answer
95 views

Catalyst discovery

How are catalysts for chemical reactions found? Given a hoped for reaction, let's take the hydrogenation of carbon monoxide to methanol as an example, do chemists: Proceed directly from some ...
1
vote
1answer
339 views

Aluminium Oxide as Dehydrating agent

According to this paper on dehydration by $\ce{Al2O3}$, Dehydroxylation causes a surface defects as Lewis acidic centers (unsaturated $\ce{Al^3+}$ ions) and basic Lewis centers ($\ce{O^2-}$ ions) ...
1
vote
0answers
36 views

Difference between Ziegler–Natta method and Phillips method [closed]

I have to compare the similarities and differences between the Zieglerr–Natta method and Phillips method of producing polyethylene. However, the only difference I can find is the difference in ...
1
vote
1answer
59 views

Can oxygen gas in air react with Mn3O4 to form MnO2?

I think $\ce{MnO2}$ at high temperature can be used as a catalyst for $\ce{SO2 + O2 -> SO3}$: $$ \begin{align} \ce{MnO2 + SO2 &-> MnSO4}\tag{1}\\ \ce{3 MnSO4 &-> Mn3O4 + SO2 + 2 SO3}\...
0
votes
2answers
75 views

Catalyst that combines oxygen and hydrogen

Are there any known catalysts that can combine hydrogen and oxygen into water? Does this type of reaction have a name? Trying to search for information, it seems to be all about splitting hydrogen ...
3
votes
0answers
209 views

Reaction between Sodium Thiosulfate and Iron Chloride

I'm doing a paper on catalytic effectiveness in this reaction, and am trying to identify how the catalysts are speeding up the reaction. Based on what I can find, $\ce{Fe}$ starts as $\ce{Fe^3+}$, ...
4
votes
0answers
54 views

CuAAC “Click” reaction giving inconsistent results

I apologize in advance for the large amount of text and thank all those who take the time to read it. The "Click" reaction after Fokin and Sharpless is known to achieve high yields without long ...
1
vote
0answers
50 views

Is activation energy directly related to the reaction rate? (keeping the temperature, concentration, catalyst, particle size and pressure constant)

For different chemical reactions, does the activation energy of that reaction directly relate to the reaction rate? In other words, would a reaction always be slower if it had a higher activation ...
1
vote
0answers
27 views

Will a Lewis acid catalyze the reaction of HBr with primary alcohols?

It is well-established that a Lewis acid catalyst (popularly $\ce{ZnCl2})$ is necessary to form an alkyl chloride when reacting $\ce{HCl}$ with a primary alcohol. This actually changes the mechanism: ...
0
votes
1answer
85 views

How can some enzymes work faster than the diffusion rates of the reactants allow?

Quoting Wikipedia: "Some enzymes operate with kinetics which are faster than diffusion rates, which would seem to be impossible." Which are those enzymes and how can they be so fast? One example is ...
1
vote
0answers
24 views

What is the equation that describes the variation in concentration of an inhibitor in an heterogeneous catalysis?

I find myself in quite a pinch: I have to sustain a Chemical Physics exam, and I know for a fact that the professor often asks this particular question: Suppose that we have both a reacting species ...
1
vote
0answers
26 views

Why isn't the base reformed in base-catalyzed hydrolysis of esters?

In acid-catalyzed hydrolysis, the hydronium ion is clearly reformed; however, in the base-catalyzed hydrolysis, an alcohol is formed as a by-product, but the strong base isn't reformed. Is it a ...
2
votes
2answers
911 views

Rate of reaction graph

An autocatalytic reaction is a reaction in which one of the products catalyses the reaction. In general what will be the shape of curve if the rate of reaction was plotted against time for an ...
0
votes
1answer
27 views

Catalysts to accelerate foamy polyurethane reaction

This is the reaction that I am referring to: https://www.youtube.com/watch?v=EoRUSo0BWC0 I am interested in finding catalysts to accelerate this fun chemistry demonstration. I have heard that some ...

1
2 3 4 5 6