Fig. 1: Structural and elemental composition of the functionalized Ag–Cu catalysts.
From: Improved electrochemical conversion of CO2 to multicarbon products by using molecular doping
a Schematic representation of the functionalized Ag–Cu electrodes in a membrane electrode assembly. b, c Cross-section (b) and top-view (c) scanning electron microscope (SEM) images of the functionalized hierarchical Ag–Cu catalyst on a gas diffusion electrode (GDE). d High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) image (left) and corresponding Cu (red) and Ag (blue) EDS elemental maps of N2SN-functionalized Ag–Cu (right). e High-resolution transmission electron microscope (HR-TEM) micrograph of the N2SN-functionalized electrode (e). f HAADF-STEM image and the corresponding Cu and S EDS elemental maps taken from a section of Cu surface on the N2SN-functionalized Ag–Cu electrode. g HAADF-STEM image of the Cu surface of N2SN-functionalized Ag–Cu. h (top), Electron energy-loss spectroscopy (EELS) elemental mapping of C taken from the area marked by the box in g. h (bottom), EELS spectrum of the C-K edge with fine structures characteristics of carbon linked to heteroatoms from N2SN layer on the Cu surface. i Raman spectra of pristine (non-functionalized) Ag–Cu (gray), C3-functionalized Ag–Cu (orange), C2N-functionalized Ag–Cu (green), N3N-functionalized Ag–Cu (purple) and N2SN-functionalized Ag–Cu (blue).
