Recently, a new mode of gas-surface heterogeneous catalysis (epicatalysis) has been identified, having potential applications ranging from industrial and green chemistry to novel forms of power generation. This article describes an inexpensive, easily constructed, vacuum-compatible apparatus by which multiple candidate gas-surface combinations can be rapidly screened for epicatalytic activity. In exploratory experiments, candidate surfaces (teflon, kapton, glass, and gold) and gases (helium, argon, cyclohexane, water, methanol, formic acid, and acetic acid) were tested for epicatalytic activity. Kapton and teflon displayed small but reproducible differences in formic acid and methanol dimer desorption, thereby demonstrating the first examples of room-temperature epicatalysis. Other gas-surface combinations showed smaller or inconclusive evidence for epicatalysis.
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http://dx.doi.org/10.1063/1.4954971 | DOI Listing |
J Phys Chem A
January 2025
School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China.
Microkinetic modeling of heterogeneous catalysis serves as an efficient tool bridging atom-scale first-principles calculations and macroscale industrial reactor simulations. Fundamental understanding of the microkinetic mechanism relies on a combination of experimental and theoretical studies. This Perspective presents an overview of the latest progress of experimental and microkinetic modeling approaches applied to gas-solid catalytic kinetics.
View Article and Find Full Text PDFJ Phys Chem Lett
October 2024
Department of Mechanical Engineering & Materials Science and Engineering Program, State University of New York at Binghamton, Binghamton, New York 13902, United States.
This study investigates the oxidation behavior of CuPt(100) in CO using a combination of ambient-pressure X-ray photoelectron spectroscopy, mass spectroscopy, and density functional theory modeling. Our in situ measurements reveal the simultaneous oxidation and reduction of CuO due to the opposing effects of atomic oxygen and CO generated from dissociative CO adsorption, leading to a dynamic equilibrium state of simultaneously occurring redox reactions. Complementary atomistic calculations elucidate the inhibitory effects of subsurface Pt enrichment and the counteracting roles of CO and CO in surface oxidation and reduction.
View Article and Find Full Text PDFPhys Chem Chem Phys
September 2024
Department of Chemistry, University of California, Irvine, CA 92697-2025, USA.
Understanding growth mechanisms for particles in air is fundamental to developing a predictive capability for their impacts on human health, visibility, and climate. In the case of highly viscous semi-solid or solid particles, the likelihood of impinging gases being taken up to grow the particle will be influenced by the initial uptake coefficient and by the residence time of the adsorbed gas on the surface. Here, a new approach that combines Knudsen cell capabilities for gas uptake measurements with temperature programmed desorption (TPD) for binding energy measurements of gases is described.
View Article and Find Full Text PDFPhys Rev E
June 2024
Institute for Multiscale Themofluids, School of Engineering, University of Edinburgh EH9 3FB, United Kingdom.
The impact of nanoscale wall roughness on rarefied gas transport is widely acknowledged, yet the associated scattering dynamics largely remain elusive. In this paper, we develop a scattering kernel for surfaces having nanoscale roughness that distinctly characterizes the two major types of interactions between gas molecules and rough surfaces. Namely these are (a) the weak perturbations arising from the thermal motion of wall atoms, essentially gas-phonon collisions, which are captured by the well-established Cercignani-Lampis model, and (b) the hard collisions owing to the irregularities of the rough, static potential energy surface, which are generally described by the fully diffuse model.
View Article and Find Full Text PDFJ Chem Phys
May 2024
The James Franck Institute and Department of Chemistry, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA.
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