Abstract The inverse oxide/metal structures represent a new class of heterogeneous catalysts with great research interests due to their diverse interfacial structures between oxides and metal supports, which often lead to unique catalytic properties. Herein, we report a facile and general strategy to prepare inverse catalysts with nanoporous structures by dealloying. As an example, inverse nanoporous Cr 2 O 3 /Cu (NP−Cr 2 O 3 /Cu) catalysts with a bi‐continuous nanoporous structure are fabricated by room temperature chemical dealloying of CrCuAl alloy in alkaline solution, which exhibit excellent performance in CO 2 reduction to CO (reverse water‐gas shift, RWGS), significantly higher performance than the traditional Cu/Cr 2 O 3 catalyst and inverse catalysts obtained by other traditional preparation methods. Density functional theory (DFT) calculation results show that CO 2 reduction is evidently promoted by the synergistic effects of Cr 2 O 3 cluster and nanoporous Cu. These results suggest a promising route for the preparation of various heterogeneous catalysts with tailored functionalities.