Questions tagged [catalysis]
This tag is appropriate for reactions, their mechanisms, their kinetics, when catalysts of any kind are involved.
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SSITKA - In Operando Transmission IR [closed]
Question:
SSITKA: a method to measure the active surface area of a catalyst while it
is under reaction conditions. This is perhaps the most accurate method
to measure the number of sites because the ...
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Pseudo rate equation for catalyzed decompostion of hydrogen peroxide
I am conducting an experiment in which I will be adding a catalyst to a solution of Hydrogen peroxide and will measure its concentration over a range of time by taking samples of the solution every $5$...
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Reduction of benzylic alcohol and halide using H2 and Pd
I am studying drug synthesis, and I found some examples that uses $\ce{H_2}$ and Pd/C or Pd/$\ce{BaSO_4}$ as catalytic hydrogenation reagents for reduction of alcohol or halide in benzylic position. ...
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How does a transition metal(eg Zn,Pd,Pt etc) break the hydrogen bond in catalytic reduction
I want to know what exactly happens with the hydrogen molecules and transition metals in catalytic reduction leading to breaking of hydrogen bonds and forming two hydrogen atoms
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Is the "heat or UV" necessary for PVC10 + Cl => CPVC10 catalytic or endothermic and if endothermic how much energy?
Production of Chlorinated PolyVinyl Chloride (CPVC) from PVC and chlorine requires incorporating about one part chlorine in 10 PCV to achieve around 63% chlorine mass CPVC. This reaction is "...
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What is the difference between using an oven or an IR lamp to dry the coatings of fuel cells?
I wondered how the morphology of the catalyst coating for fuel cells changes if it is dried either in a conventional oven (40 °C, 60°C, 80°C) or under an IR lamp.
I am pretty certain that it changes, ...
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How to determine uncompensated or solution resistance of a 3 electrode setup for IR correction?
To correct for ohmic losses from the potential drop across the electrolyte due to the distance between the electrodes, electrochemical impedance spectroscopy (EIS) is typically employed to measure ...
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Does someone know a unique testable questions surrounding 1 of the 5 variables that affect the rate of a chemical reaction? [closed]
I am a year 11 student studying high school chemistry and we are currently studying catalysts.
I am working on an assessment and need to come up with a unique but testable hypothesis surrounding one ...
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Why sulfuric acid is used in esterification of alcohol and carboxylic acid anhydride?
I have a question regarding why sulfuric acid is used in esterification of alcohol and carboxylic acid anhydride.
I know that in case of esterification of alcohol and carboxylic acid, sulfuric acid ...
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Ways and ideas to study ym rough surfaces with scanning tunneling microscopy
We want to study porous carbon (with nanoparticles, e.g., FeO, Ni, Au, La, Ir, Ag ...) via STM. But we run into the problem that the surface is very rough. As seen in Figure 1.
Thus there is an ...
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Is the line between physisorption and chemisorption species specific?
I was studying about heterogenous catalysis, and my Professor said something along the line, "When the adsorption energy is comparable to (or lower than) heat of evaporation, then it is ...
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Substitution of aryl bromide in synthesis of a chelator
Hello I am currently working on a synthesis of a chelator for the synthesis of a photosensitizer for photodynamic therapy. My instructor wants me to do following synthesis procedure:
My problem is, ...
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Hydrolysis of polyamides using solid acid catalyst
The neutral hydrolysis of polyamides (eg. nylon 6,6) does not go to completion as the reaction is reversible. You can get around this by carrying out the reaction in an acidic/basic medium. With acid ...
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Effectivness factor for a cylinder
I would like to demonstrate the effectiveness factor of a porous cylinder, for diffusion-reaction (only radial diffusion, 1st order reaction, isothermal, diffusion coeff. is constant, steady-state), ...
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2
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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 ...
2
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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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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)}$$
Here, manganese dioxide is behaving as a ...
user85778
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Rate equation for the decomposition of hydrogen peroxide with iron(III) chloride as catalyst [duplicate]
I am trying to determine the activation energy of the decomposition of hydrogen peroxide with iron(III) chloride added as a catalyst. To do that, I need to find the rate constant, but I am not sure ...
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Inhibitors reaction at home
For a school science project, my teacher asked me to find a reaction that can be slowed down with an inhibitor and film it at home/lab at school. He told not to use lemon on an apple or anything ...
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How to promote oxidation of copper(I) chloride to copper(II) chloride with oxygen in solution?
I recently discovered that copper(I) chloride in hydrochloric acid can react at about 80 °C with bubbled-in oxygen gas and oxidize into copper(II) chloride. I found almost no documentation on the web, ...
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When doing free radical substitution, is the free radical a catalyst?
Consider a simple free radical substitution's propagation step for $\ce{CH4}$ to $\ce{CH3Cl}$:
$$
\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 ...
