Matteo Monai
@matteomonai.bsky.social
Chemist, ARC CBBC Assistant Professor at Utrecht University, bass player
Congrats, Joyce Kromwijk and the team, Job Vloedgraven, Fleur Neijenhuis, Ward van der Stam, and Bert Weckhuysen.
April 22, 2025 at 6:00 PM
Congrats, Joyce Kromwijk and the team, Job Vloedgraven, Fleur Neijenhuis, Ward van der Stam, and Bert Weckhuysen.
To end, a few provocative questions:
When is a catalyst (in)active?
Should we give up on a "bad" catalyst after a 1-hour run?
If not, how long shall we wait for a lazy catalyst that might just need a "long morning routine" (cit. Joyce) before getting to work?
When is a catalyst (in)active?
Should we give up on a "bad" catalyst after a 1-hour run?
If not, how long shall we wait for a lazy catalyst that might just need a "long morning routine" (cit. Joyce) before getting to work?
April 22, 2025 at 5:59 PM
To end, a few provocative questions:
When is a catalyst (in)active?
Should we give up on a "bad" catalyst after a 1-hour run?
If not, how long shall we wait for a lazy catalyst that might just need a "long morning routine" (cit. Joyce) before getting to work?
When is a catalyst (in)active?
Should we give up on a "bad" catalyst after a 1-hour run?
If not, how long shall we wait for a lazy catalyst that might just need a "long morning routine" (cit. Joyce) before getting to work?
All in all, this is a reminder of how a seemingly simple system can hide tremendous complexity.
In the words of Henry Taube, 1983 Nobel Prize in Chemistry, "There is still so much beyond our understanding, even in the simplest systems the chemist has cared to deal with."
In the words of Henry Taube, 1983 Nobel Prize in Chemistry, "There is still so much beyond our understanding, even in the simplest systems the chemist has cared to deal with."
April 22, 2025 at 5:59 PM
All in all, this is a reminder of how a seemingly simple system can hide tremendous complexity.
In the words of Henry Taube, 1983 Nobel Prize in Chemistry, "There is still so much beyond our understanding, even in the simplest systems the chemist has cared to deal with."
In the words of Henry Taube, 1983 Nobel Prize in Chemistry, "There is still so much beyond our understanding, even in the simplest systems the chemist has cared to deal with."
(We think in the 10 wt. % case, redispersion is hindered because the catalyst surface is too crowded, and reduction by C species is involved in the activation pathway.)
April 22, 2025 at 5:59 PM
(We think in the 10 wt. % case, redispersion is hindered because the catalyst surface is too crowded, and reduction by C species is involved in the activation pathway.)
Not only that, there seems to be a sweet spot:
A 2 % W catalyst cannot activate. This suggests that very highly dispersed W does not do the trick.
...And if you try to apply the same thermal activation to a 10 % W catalyst, the induction time becomes longer (up to 350 min).
Such a lazy catalyst!
A 2 % W catalyst cannot activate. This suggests that very highly dispersed W does not do the trick.
...And if you try to apply the same thermal activation to a 10 % W catalyst, the induction time becomes longer (up to 350 min).
Such a lazy catalyst!
April 22, 2025 at 5:58 PM
Not only that, there seems to be a sweet spot:
A 2 % W catalyst cannot activate. This suggests that very highly dispersed W does not do the trick.
...And if you try to apply the same thermal activation to a 10 % W catalyst, the induction time becomes longer (up to 350 min).
Such a lazy catalyst!
A 2 % W catalyst cannot activate. This suggests that very highly dispersed W does not do the trick.
...And if you try to apply the same thermal activation to a 10 % W catalyst, the induction time becomes longer (up to 350 min).
Such a lazy catalyst!
It seemed that a thermally-induced restructuring was needed to activate the catalyst...
But what had happened precisely?
Long story short, our results suggest that tungsten must redisperse, forming small clusters, to be activated (with an apparent activation energy exceeding 700 kJ/mol).
But what had happened precisely?
Long story short, our results suggest that tungsten must redisperse, forming small clusters, to be activated (with an apparent activation energy exceeding 700 kJ/mol).
April 22, 2025 at 5:57 PM
It seemed that a thermally-induced restructuring was needed to activate the catalyst...
But what had happened precisely?
Long story short, our results suggest that tungsten must redisperse, forming small clusters, to be activated (with an apparent activation energy exceeding 700 kJ/mol).
But what had happened precisely?
Long story short, our results suggest that tungsten must redisperse, forming small clusters, to be activated (with an apparent activation energy exceeding 700 kJ/mol).
Since long induction times can be evidence of auto-catalysis, we thought W was slowly reacting with CH4, followed by a fast activation.
To disprove this, we treated the catalyst in inert for 100 min, and only then switched to methane.
Well, the catalyst got right to work, making benzene right away!
To disprove this, we treated the catalyst in inert for 100 min, and only then switched to methane.
Well, the catalyst got right to work, making benzene right away!
April 22, 2025 at 5:56 PM
Since long induction times can be evidence of auto-catalysis, we thought W was slowly reacting with CH4, followed by a fast activation.
To disprove this, we treated the catalyst in inert for 100 min, and only then switched to methane.
Well, the catalyst got right to work, making benzene right away!
To disprove this, we treated the catalyst in inert for 100 min, and only then switched to methane.
Well, the catalyst got right to work, making benzene right away!
The expectations were clear: W oxide would react with methane, form active (oxy)carbides, CO, benzene and carbon.
However, when testing the catalyst, nothing happened... Radio silence.
Luckily, it was an overnight experiment. After 100 min, the catalyst suddenly "woke up" and started making benzene.
However, when testing the catalyst, nothing happened... Radio silence.
Luckily, it was an overnight experiment. After 100 min, the catalyst suddenly "woke up" and started making benzene.
April 22, 2025 at 5:54 PM
The expectations were clear: W oxide would react with methane, form active (oxy)carbides, CO, benzene and carbon.
However, when testing the catalyst, nothing happened... Radio silence.
Luckily, it was an overnight experiment. After 100 min, the catalyst suddenly "woke up" and started making benzene.
However, when testing the catalyst, nothing happened... Radio silence.
Luckily, it was an overnight experiment. After 100 min, the catalyst suddenly "woke up" and started making benzene.
Joyce Kromwijk was working on alternatives to molybdenum/zeolite catalysts for the methane conversion to aromatics via methane dehydroaromatization (MDA). Because she wanted to perform the MDA reaction in tandem with CO2 methanation, she chose the more robust tungsten (W/ZSM-5) as alternative.
April 22, 2025 at 5:51 PM
Joyce Kromwijk was working on alternatives to molybdenum/zeolite catalysts for the methane conversion to aromatics via methane dehydroaromatization (MDA). Because she wanted to perform the MDA reaction in tandem with CO2 methanation, she chose the more robust tungsten (W/ZSM-5) as alternative.
The last paragraph is 🧨
April 18, 2025 at 5:44 PM
The last paragraph is 🧨
Our tv is in an actual fireplace, so who’s stopping us?
December 1, 2024 at 4:37 PM
Our tv is in an actual fireplace, so who’s stopping us?
And that is why not all heroes wear capes
November 21, 2024 at 5:34 PM
And that is why not all heroes wear capes