Tracking the Prelude of the Electroreduction of Carbon Monoxide Via its Interaction With Cu(100): Studies by Operando Scanning Tunneling Microscopy and Infrared Spectroscopy

Publication date: Available online 24 January 2020Source: Catalysis TodayAuthor(s): Jack H. Baricuatro, Youn-Geun Kim, Carol L. Korzeniewski, Manuel P. SoriagaABSTRACTThe first isolable intermediate in the electrochemical reduction of carbon dioxide is carbon monoxide. This species, or its hydrated form, formic acid, is also the primary end product from all but a handful of metallic electrodes; with the latter, hydrogen gas is generated, but it emanates from the reduction of water and not from CO2. Only one electrode material, zerovalent copper, can spawn, in greater-than-trace quantities, a variety of species that are more highly reduced than CO. Hence, if the aim is to extract a reaction trail of the reduction of CO2 to products other than CO, it would be both logical and expedient to track the electrocatalytic reaction of CO itself. Heterogeneous electrocatalysis is a surface phenomenon; it transpires only when the reactant, CO in this case, chemisorbs on, or chemically interacts with, the Cu electrode surface. There is no electrocatalytic reaction if there is no CO adsorption. In ultrahigh vacuum, no CO resides on the Cu(100) surface at temperatures higher than 200 K. However, under electrochemical conditions, CO is chemisorbed on Cu at ambient temperatures at a given potential. We thus paired, in seriatim fashion, scanning tunneling microscopy (STM) and polarization-modulation IR reflection-absorption spectroscopy (PMIRS) to document the influence of applied potential ...
Source: Catalysis Today - Category: Chemistry Source Type: research