Carbon dioxide (CO2) is the major greenhouse
gas and
also an abundant and renewable carbon resource. Therefore, its chemical
conversion and utilization are of great attraction for sustainable
development. Especially, reductive conversion of CO2 with
energy input has become a current hotspot due to its ability to access
fuels and various important chemicals. Nowadays, the controllable
CO2 hydrogenation to formic acid and alcohols using sustainable
H2 resources has been regarded as an appealing solution
to hydrogen storage and CO2 accumulation. In addition,
photocatalytic CO2 reduction to CO also provides a potential
way to utilize this greenhouse gas efficiently. Besides direct CO2 hydrogenation, CO2 reductive functionalization
integrates CO2 reduction with subsequent C–X (X
= N, S, C, O) bond formation and indirect transformation strategies,
enlarging the diverse products derived from CO2 and promoting
CO2 reductive conversion into a new stage. In this Perspective,
the progress and challenges of CO2 reductive conversion,
including hydrogenation, reductive functionalization, photocatalytic
reduction, and photocatalytic reductive functionalization are summarized
and discussed along with the key issues and future trends/directions
in this field. We hope this Perspective can evoke intense interest
and inspire much innovation in the promise of CO2 valorization.