Super-resolution Imaging of Nonfluorescent Surface Reactions on Catalysts
Abstract
Nanoparticles can catalyze a multitude of important reactions, including the destruction of chemical warfare agents, fuel production in (photo)electrochemical cells, and fuel oxidation in fuel cells. Tremendous progress has been made and continue to advance in understanding the catalytic properties of nanoparticle catalysts or solid catalysts in general. However, a general experimental challenge remains: their intrinsic heterogeneity, which calls upon high-resolution methods that can interrogate the catalytic properties of individual nanoparticles in real time, with high spatiotemporal resolution, and under operando conditions. The PIÕs group has pioneered the development of single-molecule fluorescence microscopy-based methods to study catalysis on single nanoparticles, with nanometer spatial resolution, single-reaction temporal resolution, and under ambient operando conditions. The associated studies, as well as othersÕ in the field, have generated many insights into catalysis on surfaces. But the technique primarily relies on studying fluorogenic reactions, whereas most of chemical processes do not involve fluorescent species and are thus not directly measurable. To tackle this barrier, the PIÕs group has developed COMPEITS Ñ a ÒCOMPetition-Enabled Imaging Technique with Super-resolution,Ó that enables quantitative super-resolution imaging of nonfluorescent processes. COMPEITS is generalizable and opens the possibility to study many chemical processes, but its current implementation still faces limitations. The overall objective of this new proposal is to further develop and apply super-resolution imaging approaches for studying nonfluorescent reactions on catalyst surfaces at nanometer resolution and under in situ or operando conditions with the ultimate goal of acquiring fundamental knowledge for catalyst improvement and design. The proposed research comprises two aims, each with a set of sub-aims. Aim 1: Develop a new variant of COMPEITS, called adCOMPEITS, for super-resolution imaging of nonfluorescent reactions. The research activities will focus on model nanocatalysts and model reactions for benchmarking the new method but also with their own scientific significances. Aim 2: Map reactant and product adsorption landscapes on interfacially structured catalysts at nanometer resolution. The research here will use different variations of COMPEITS to map the adsorption of molecular species at metal catalyst grain boundaries and on single shaped bimetallic core-shell nanoparticles in the context of CO2 reduction and ammonia synthesis. The research is expected to have the following significances, broader impacts, and transformative nature: (1) It will provide novel quantitative, nanometer resolution optical imaging techniques for catalyst characterization under ambient solution conditions in situ or in operando, especially in mapping surface reactions that do not involve fluorescent species. (2) It will provide fundamental insights on molecular adsorption processes, including adsorption affinity and cooperativity, at different sites on catalysts for generating value chemicals from renewable sources, which will also help understand the catalytic mechanisms. (3) It will contribute to AROÕs mission by advancing knowledge about catalytic processes at solid-liquid interfaces, an important goal of the Reactive Chemical Systems program, and about catalytic formation of fuel molecules and explosive precursors from renewable sources, supporting ArmyÕs missions. (4) It represents pioneering efforts in super-resolution imaging of nonfluorescent processes by optical microscopy, which may transform the experimental landscape in studying catalysis at high spatial resolution in operando, including the extension toward gaseous molecule adsorption onto catalyst surfaces in solution conditions.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 24, 2023
- Source ID
- W911NF2310105
Entities
People
- Peng Chen
Organizations
- Army Contracting Command
- Cornell University
- United States Army