A copper–zirconia composite having an evenly distributed
lamellar texture, Cu#ZrO2, was synthesized by promoting
nanophase separation of the Cu51Zr14alloy precursor
in a mixture of carbon monoxide (CO) and oxygen (O2). High-resolution
electron microscopy revealed that the material consists of interchangeable
Cu and t-ZrO2phases with an average thickness of 5 nm.
Cu#ZrO2exhibited enhanced selectivity toward the generation
of formic acid (HCOOH) by electrochemical reduction of carbon dioxide
(CO2) in aqueous media at a Faradaic efficiency of 83.5%
at −0.9 V versus the reversible hydrogen electrode. In situ
Raman spectroscopy has revealed that a bifunctional interplay between
the Zr4+sites and the Cu boundary leads to amended reaction
selectivity along with a large number of catalytic sites.