  Electrocatalytic CO$_2$RR is an interfacial process, involving a minimum of
three phases at the contact point of gaseous CO$_2$ with the electrodic surface
and the liquid electrolyte. As a consequence, surface chemistry at composite
interfaces plays a central role for CO$_2$RR selectivity and catalysis. Each
interface defines a functional boundary, where active sites are exposed to a
unique environment with respect to distal sites in the bulk or organic and
inorganic materials. While the individual role of each component-type is hardly
predictable a-solo, the interface ensemble works via a strategic interplay of
individual effects, including: (i) enhanced electrical conductivity, (ii) high
surface area and exposure of the interfacial catalytic sites, (iii) favorable
transport and feeding of reactants, (iv) complementary interactions for the
on/off stabilization of cascade intermediates, (v) a secondary sphere
assistance to lower the activation energy of bottleneck steps, (vi) a
reinforced robustness and long-term operation stability by mutual protection
and/or healing mechanisms. Selected CO$_2$RR case studies are compared and
contrasted to highlight how the organic domains of carbon nanostructures merge
with metal and metal-oxide active sites to separate tasks but also to turn them
into a cooperative asset of mutual interactions, thus going beyond the classic
Divide et Impera rule.
