Efficient upgrading of CO to C(3) fuel using asymmetric C-C coupling active sites

The electroreduction of C(1) feedgas to high-energy-density fuels provides an attractive avenue to the storage of renewable electricity. Much progress has been made to improve selectivity to C(1) and C(2) products, however, the selectivity to desirable high-energy-density C(3) products remains relatively low. We reason that C(3) electrosynthesis relies on a higher-order reaction pathway that requires the formation of multiple carbon-carbon (C-C) bonds, and thus pursue a strategy explicitly designed to couple C(2) with C(1) intermediates. We develop an approach wherein neighboring copper atoms having distinct electronic structures interact with two adsorbates to catalyze an asymmetric reaction. We achieve a record n-propanol Faradaic efficiency (FE) of (33 ± 1)% with a conversion rate of (4.5 ± 0.1) mA cm(−2), and a record n-propanol cathodic energy conversion efficiency (EE(cathodic half-cell)) of 21%. The FE and EE(cathodic half-cell) represent a 1.3× improvement relative to previously-published CO-to-n-propanol electroreduction reports.