Title: Recycling CO2
Matthew Kanan
Stanford University
Abstract
Controlling the atmospheric CO2 concentration may ultimately require recycling CO2 into
liquid fuels and commodity chemicals using renewable energy as the power source.
Arguably the greatest challenge for this vision is to develop efficient catalysts that reduce
CO2 and its derivatives to a fuel of choice. This talk will describe our development of
“oxide-derived” nanocrystalline electrocatalysts. These materials are prepared by reducing
metal oxide precursors to form continuous networks of interconnected metal nanocrystals
with a high density of grain boundaries. The process of metal oxide reduction kinetically
traps metastable structures with unique catalytic properties. We have developed oxidederived nanocrystalline catalysts that reduce CO2 either to CO and operate at diffusionlimited current densities at potentials very close to the thermodynamic minimum. We have
also developed oxide-derived catalysts that selectively reduce CO to ethanol and acetate.
The catalysts all operate in water at ambient temperature and pressure and are remarkably
robust. The structural origins of the catalytic activity will be discussed as well as the
prospects of preparing nanocrystalline catalysts by alternative syntheses. Oxide-derived
nanocrystalline materials enable electrochemical conversions that could make CO2 a
valuable feedstock for synthetic liquid fuel.