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Justin Bui @justincbui.com · 21/08/2025

Collectively, this work reveals the immense importance of invoking a true multi-scale picture of catalysis when modeling, because mesoscale mass transfer, nanoscale double layer structure, and molecular energetics all interplay non-intuitively and have critical effects that dictate observed rates!

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Justin Bui @justincbui.com · 21/08/2025

Finally, we extend the model to explore how it can explain enhancements in CO2R observed upon the use of an inert salt that suppresses dielectric constant. This is a first step into understanding the role of non-standard solvent environments in CO2R and their effects on catalysis.

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Justin Bui @justincbui.com · 21/08/2025

This shows that the terms that we so-often like to neglect as chemical engineers become really important in the concentrated environment of the electrical double layer, which is the environment in which electrocatalysis occurs!

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Justin Bui @justincbui.com · 21/08/2025

Sensitivity analysis on the model reveals the importance of the solvent permittivity, the role of mass transfer, and the importance of each of the non-ideal terms in the excess chemical potential in enabling accurate prediction of rates.

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Justin Bui @justincbui.com · 21/08/2025

The reduced reorganization energy increases the rate of CO2R as predicted by a Marcus-Hush-Chidsey framework for electron-transfer-limited coupled-ion-electron-transfer employed in our continuum model.

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Justin Bui @justincbui.com · 21/08/2025

This allows us to really get to the heart of how the double layer structure controls rates in CO2R. Smaller hydrated cations pack more tightly in the EDL, which increases local electric fields, lowering dielectric permittivity, and correspondingly reducing the solvent reorganization energy.

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Justin Bui @justincbui.com · 21/08/2025

The model employs zero adjustable parameters, and faithfully and quantitatively predicts the rate of CO2RR as a function of cation, electrolyte strength, and CO2 activity, as well as the local pH and CO2 activity measured by ATR-SEIRAS!

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Justin Bui @justincbui.com · 21/08/2025

We also find that having an accurate double layer structure in the simulation allows us to get very accurate predictions of catalytic rates in our continuum model.

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Justin Bui @justincbui.com · 21/08/2025

In this work, we develop a multi-scale model of the electrical double layer in CO2 reduction. By including a variety of non-ideal ion-specific effects, such as cation hydrolysis, steric excess potentials, and more, we can accurately the structure of the double layer as confirmed by impedance.

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Justin Bui @justincbui.com · 21/08/2025

Super excited to share @Alex_James_King and my work on elucidating the role of the double layer in electrochemical CO2 reduction! This work has been years in the making, and excitingly, starts to get to the heart of how cations control rates of CO2R! pubs.acs.org/doi/full/10....

pubs.acs.org

Revealing the Role of the Electrical Double Layer in Electrochemical CO2 Reduction

The electrical double layer (EDL) has long been known to influence observed rates of electrocatalysis, but a complete understanding of its role has been elusive due to the complex, multicomponent inte...

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Justin Bui @justincbui.com · 02/04/2025

Incredibly honored to be a member of this year’s Schmidt Science Fellows Cohort! I am very excited to leverage this unprecedented opportunity to pivot into AI and automation to build autonomous flow reactors for optimizing electro organic synthesis. #chemsky 🧪 #compchemsky

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Justin Bui @justincbui.com · 09/03/2025

I am co-chairing a session for @acs.org Fall 2024 on engineering systems and microenvironments for electrochemical CO2 reduction. We think it'll be a great session and encourage anyone interested to submit abstracts! Due date is March 31! #Science #ChemSky #CompChemSky

Oral and poster sessions for Engineering CO2 Reduction environments

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Justin Bui @justincbui.com · 21/12/2024

Sharing our recent work on continuum modeling of forward bias bipolar membranes for more visibility with #ChemSky and #CompChemSky! As always I am happy to answer any questions about this work! 🧪

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Justin Bui @justincbui.com · 20/12/2024

Finally, thanks to @ucberkeleyofficial.bsky.social and @berkeleylab.bsky.social for being such a great home to work on BPM research for the last 5 years. Super proud of all that we were able to do together on this topic, and looking forward to watching this space in the future! (11/11)

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Justin Bui @justincbui.com · 20/12/2024

I also want to give a special shoutout to my former undergraduate mentee, Andrew Liu who performed many of the initial simulations that provided the groundwork for the findings in this work. (10/11)

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Justin Bui @justincbui.com · 20/12/2024

This work was a massive team effort and could not have been done without my exceptional collaborators, Eric Lees, James Toh, Nathan Stovall, Priyamvada Goyal, and Kiko Galang, along with the support of our PIs, Adam Weber, Alexis Bell, and Yogi Surendranath. (9/11)

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Justin Bui @justincbui.com · 20/12/2024

Finally, we highlight potential routes to alleviate these challenges, identifying that rational materials design of BPMs with high concentrations of selective fixed-charge will be pivotal to enabling these future technologies! (8/11)

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Justin Bui @justincbui.com · 20/12/2024

For this reason, CO2 absorption into the AEL as carbonates is an existential challenge for FB-BPMs, because divalent carbonate anions thoroughly outcompete OH- for recombination sites at the interface. (7/11)

Influence of carbon dioxide absorption on limiting current density in forward-biased bipolar membranes.

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Justin Bui @justincbui.com · 20/12/2024

Multi-component phenomena complicate matters further by reducing the number of available sites for recombination, highlighting the importance of designing membranes selective to H+ or OH-, whose recombination reaction represents the highest achievable current and voltage. (6/11)

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Justin Bui @justincbui.com · 20/12/2024

Second, mismatch between the counter-ion fluxes induces observed limiting current densities in forward bias, because when one ion becomes limiting relative to the other, the species in excess will cross-over through the junction and attenuate the achievable voltage. (5/11)

Process of limiting current density in forward-biased bipolar membranes.

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Justin Bui @justincbui.com · 20/12/2024

First, the pKa of the recombination product formed at the AEL|CEL interface and the valency of the recombining ion dictate the open circuit potential of the system, because the OCP is achieved at the point where counter-ion recombination and co-ion crossover are balanced. (4/11)

Figure showing the role of conjugate acid pKa on the open circuit potential of a bipolar membrane.

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Justin Bui @justincbui.com · 20/12/2024

We sought to understand these limitations through continuum modeling of the multi-component transport and reaction kinetics occurring in these systems. Ultimately, we reveal some interesting and non-intuitive phenomena that limit the performance of FB-BPMs. (3/11)

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Justin Bui @justincbui.com · 20/12/2024

There are many applications where forward-biased BPMs can be useful, from self-humidifying hydrogen fuel cells, to lower voltage electrolyzers, and even to acid-base recombination batteries. However, these systems have long been limited in the rates that they can achieve. (2/11)

Applications of forward-biased bipolar membranes.

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Justin Bui @justincbui.com · 20/12/2024

This work focuses on the physics of bipolar membranes (BPMs) operating in the forward bias configuration, wherein counter-ions transport to the bipolar interface to recombine. Amazingly, voltage can be recovered from this recombination reaction! (1/11)

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Justin Bui @justincbui.com · 05/12/2024

Thanks!! Appreciate your hard work moderating this feed!!

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Justin Bui @justincbui.com · 05/12/2024

Hi! I’m an incoming professor at NYU who works in the area of electrochemistry and catalysis. (engineering.nyu.edu/faculty/just...) I would greatly appreciate being added to this feed! Thank you!

engineering.nyu.edu

Justin Bui | NYU Tandon School of Engineering

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Justin Bui @justincbui.com · 03/12/2024

Wow!!! What technology was that made with?

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Justin Bui @justincbui.com · 03/12/2024

To my PhD advisors Alex Bell and Adam Weber, who gave me the tools to tackle and contribute to hard problems in energy. To my postdoc advisor Karthish Manthiram, who has always believed in my science and continues to encourage me to “shoot for the fences.” These awards are never won alone! (6/6)

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Justin Bui @justincbui.com · 03/12/2024

I’d be remiss if I didn’t thank some of the amazing supporters I’ve had throughout my scientific journey. It’s impossible to list everyone but here’s a few! From Dan Esposito who gave me my introduction to electrochemistry and has remained a constant supporter. (5/6)

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Justin Bui @justincbui.com · 03/12/2024

This focus on translation will be core to my work at NYU! Already, wheels are in motion for industry collaboration with companies like Turnover Labs, which is currently running some operations out of NYU (among others!). Hopefully, tech we develop in our lab will also make out into the world! (4/6)

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Justin Bui @justincbui.com · 03/12/2024

In my PhD, I had a few opportunities to work with the amazing CX Xiang, Harry Atwater, and Eowyn Lucas of Captura to help model, understand, and optimize the bipolar membranes that are key components in their CO2 capture system! Getting to work with them was a highlight of my PhD! (3/6)

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Justin Bui @justincbui.com · 03/12/2024

I’ve always sought out opportunities to work on projects with translational impact, and have been very lucky to get to contribute to such systems! As an undergrad, my work developing membraneless electrolyzers with Prof. Dan Esposito at Columbia eventually became a part of his start-up, sHyp. (2/6)

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Justin Bui @justincbui.com · 03/12/2024

Insanely honored to be part of this year’s Forbes 30 Under 30 in Science. It is also interesting to see them highlight some of the translational aspects of my past scientific research that I do not talk about as much on here! 🧵 below: (1/6) www.forbes.com/30-under-30/...

forbes.com

Forbes 30 Under 30 2024: Science

Inventing the future from the atom up

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Justin Bui @justincbui.com · 02/12/2024

Tip for academics coming to #ChemSky! You can set your handle to your personal or lab website! This effectively serves as a decentralized account verification ✅. We no longer have to rely on someone to give us (or sell us) a "Blue Check"! Takes 5 Min; Details Here: bsky.social/about/blog/4...

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Justin Bui @justincbui.com · 02/12/2024

The challenges with Li intercalation when using Carbon based electrodes are something we discuss quite frequently in the Manthiram Lab here at Caltech! So cool to see such a clever solution to this problem here.

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Justin Bui @justincbui.com · 28/11/2024

No better way to cap off the year than to get to see my thesis fully in print! 📕 In the fashion of Thanksgiving, I just want to say how grateful I am to everyone who helped make this possible. Thankful everyday to have the opportunity to do this work alongside great colleagues!

Photograph of the Printed Copy of Justin Bui's Thesis on Modeling Bipolar Membranes.

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Justin Bui @justincbui.com · 28/11/2024

That’s awesome! Looks great!!

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Justin Bui @justincbui.com · 28/11/2024

Spent some time in the Bobst Library at NYU for the first time this past week! What a great place to analyze some NMR!!

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Justin Bui @justincbui.com · 25/11/2024

No questions of what I’ve been working on these past few years! #CO2 #membranes Hopefully I can add some new words to this cloud soon in the next chapter of my career! #chemsky #greensky Credits: @scholargoggler.bsky.social

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Reposted by Justin Bui

Prashant Kamat @kamat.bsky.social · 25/11/2024

Here is a new starter pack to follow some electrochemists (More to come) go.bsky.app/UzqjkNk

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Justin Bui @justincbui.com · 25/11/2024

Thanks for putting this together, Prashant! Great list!

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