We have developed a new scanning probe approach for the delivery of a gas-phase reactant to the surface of an electrocatalyst through a self-replenishing bubble located at the end of a scanning probe. This approach enables local electrocatalytic rates to be detected under very-high mass transport rates due to the small distance between the gas-phase reactant in the bubble and the electrocatalyst surface. Here we report experiments for the delivery of carbon dioxide to a gold ultramicroelectrode surface using a micron-scale nanopipette. The approach curve profiles that we measure suggest a complex interplay between carbon dioxide reduction and hydrogen evolution which is mediated by both the probe-electrode distance and the potential of the gold ultramicroelectrode.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1039/d4fd00124a | DOI Listing |
J Chem Theory Comput
January 2025
Department of Chemistry, Rice University, Houston, Texas 77005-1892, United States.
Generalized Hartree-Fock (GHF) is a long-established electronic structure method that can lower the energy (compared to spin-restricted variants) by breaking physical wave function symmetries, namely and . After an exposition of GHF theory, we assess the use of GHF trial wave functions in phaseless auxiliary field quantum Monte Carlo (ph-AFQMC-G) calculations of strongly correlated molecular systems including symmetrically stretched hydrogen rings, carbon dioxide, and dioxygen. Imaginary time propagation is able to restore symmetry and yields energies of comparable or better accuracy than CCSD(T) with unrestricted HF and GHF references, and consistently smooth dissociation curves─a remarkable result given the relative scalability of ph-AFQMC-G to larger system sizes.
View Article and Find Full Text PDFJ Arrhythm
February 2025
Arrhythmia and Electrophysiology Unit, Department of Cardiology Hacettepe University Faculty of Medicine Ankara Turkey.
J Arrhythm
February 2025
Heart Rhythm Center and Division of Cardiology, Department of Medicine Taipei Veterans General Hospital Taipei Taiwan.
Carbon dioxide injection through coronary vein puncture can greatly reduce complications from epicardial access. We reported a case of ventricular tachycardia that was successfully ablated by this procedure under ECMO support.
View Article and Find Full Text PDFNanoscale
January 2025
Center for Energy and Environmental Sciences, Paul Scherrer Institute, Forschungsstrasse 111, 5232, Villigen, Switzerland.
The strong influence of surface adsorbates on the morphology of a catalyst is exemplified by studying a silver surface with and without deposited zinc oxide nanoparticles upon exposure to reaction gases used for carbon dioxide hydrogenation. Ambient pressure X-ray photoelectron spectroscopy and scanning tunneling microscopy measurements indicate accumulation of carbon deposits on the catalyst surface at 200 °C. While oxygen-free carbon species observed on pure silver show a strong interaction and decorate the atomic steps on the catalyst surface, this decoration is not observed for the oxygen-containing species observed on the silver surface with additional zinc oxide nanoparticles.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!