We design, synthesize, characterize and test materials for heterogeneous catalysis and photocatalysis. Our focus is on reactions revolving around energy and environmental themes, with emphasis on the chemistry of small building blocks that are at the heart of past, present and future history: hydrogen, carbon dioxide, methane, water, nitrogen.
The starting point for our studies are well-defined nanocrystals and nanostructures, and we tune and tailor their architecture at the atomic level to understand how a specific structure influences the final properties of the system. We prepare and study our materials by using state-of-the-art synthetic and characterization techniques that include colloidal and supramolecular chemistry, advanced microscopy, x-ray-based spectroscopies and functional testing in our ~1600 sq ft brand new lab in the Shriram center and, more in general, using the great facilities located at Stanford and in the nearby SLAC national laboratory.
Our goal is to help the planet transition to a cleaner and sustainable future, where resources are available to a larger part of the population and the economic growth is accompanied by an improvement in the living conditions and in the quality of the environment. We are motivated by big challenges that mankind has to face, and we want to contribute in our own way: using small, tiny particles, or nanocrystals, to speed-up chemical reactions that can provide sustainable fuels and chemicals and reduce pollution.
Each of us in the group has her/his own independent project, yet connected to the bigger picture, like a piece of the puzzle. We believe that only team work, motivation and dedication can indeed advance science and provide us with solutions. If you share our values, join us in this exciting journey!
3 December 2018: Collaborative work led by Janis Timoshenko and Anatoly Frenkel, with help from Cody, on using neural networks to analyze the structure of mono- and bimetallic materials has been published in Nano Letters! Read it here
25 September 2018: Aisulu's and Liheng's work on restructuring of Ru-ceria catalysts for CO2 reduction, in collaboration with Simon Bare's group at SSRL, has been published in JACS! Read it here
17 September 2018: Cody's work, in collaboration with Simon Bare's group at SSRL, on Pd/Au diluted alloys for selective oxidations is now out in JACS! Read it here
16 August 2018: Our team work led by Emmett on using Ru nanocrystals (and a sprinkle of Pd) to efficiently convert methane into syngas is now out! Read it here
19 July 2018: Alex's work on identifying Marangoni flow during graphene deposition as a barrier for obtaining high quality films by Langmuir-Blodgett technique has been accepted in Langmuir! Read it here
We are in urgent need of sustainable energy generation processes, energy vectors, and solutions to reduce pollution and greenhouse gas emissions.
Active, stable and selective
We are studying synthetic ways to make catalysts not only more active, but also more selective and more stable by exploiting confinement effects in which nanocrystals and active phases are embedded inside 3-dimensional cavities.
We study nanostructures that have precise sizes and/or structures and use them to answer fundamental questions regarding reaction mechanisms. This fundamental knowledge allows us (and others) to prepare even better catalysts.
We envision materials that can use light as an energy input to convert compounds and pollutants into valuable chemicals, such that chemical processes could be run sustainably at room temperature and pressure.
CHEMENG 31N: When Chemistry Meets Engineering, Fall 2018 Chemistry and engineering are subjects that are ubiquitous around us. But what happens when the two meet? Students will explore this question by diving into experimental problems that scientists and engineers have to face on a daily basis. Many processes that are taken for granted have been developed by understanding science at a very fundamental level and then applying it to large and important industrial processes. In this seminar, students will explore some of the basic concepts that are important to address chemical engineering problems through experimental work. Students will build materials for energy and environmental applications, understand how to separate mixtures into pure compounds, produce fuels, and will learn to look at the chemical properties of molecules that are part of daily life... with a different eye.
CHEMENG 345: Fundamentals and Applications of Spectroscopy, Winter 2019 Development of theoretical approaches to spectroscopy, including spectroscopic transitions, transition probabilities, and selection rules. Application to photon and electron spectroscopies of the gas and solid phases. Topics: rotational spectroscopy; infrared and Raman vibrational spectroscopies; fluorescence spectroscopy; Auger, x-ray and ultraviolet photoelectron spectroscopies.
CHEMENG 130: Separation Processes, Spring 2019 Analysis and design of equilibrium and non-equilibrium separation processes. Possible examples: distillation, liquid-liquid extraction, flash distillation, electrophoresis, centrifugation, membrane separations, chromatography, and reaction-assisted separation processes.
The Cargnellogroup moved into its new lab in January 2016 and started to cook some great science. Stay hungry!
Synthesis hoods, gas phase lines, furnaces, equipment for structural and catalytic characterization of our materials are available.
Hades is the first reactor built in the group. Gases are delivered to a U-shaped reactor through flowmeters, and the reactor is heated by a furnace that can reach temperatures of 1100 C. The gases are analyzed by an on-line gas chromatograph with TCD and FID detectors.
Gas-phase Reaction Lines
Our reaction lines are custom-made by us to achieve the highest flexibility and reliability in the application space and in the accuracy of our experiments.
Our Schlenk lines allow us to synthesize nanocrystals under appropriate conditions (air-free and water-free). Inert reaction conditions are indeed very important for controlling their size, shape and composition.
A physi- and chemisorption system (Micromeritics) is available in the group to measure the morphology and textural properties of our materials, and the accessibility of active metal phases in supported catalysts.
FT-IR and Gas Cell
An FT-IR system (Nicolet) equipped with a gas cell is used for the detection of molecules in complex mixtures. It is connected to a thermal reactor and an electrochemical reactor.
Our nitrogen-filled glovebox (LC technologies) gives us the opportunity to handle air-sensitive precursors and products, and perform operations under an inert atmosphere.
The group has several furnaces that are used to perform thermal treatment to our materials before they are used in catalytic transformations.