Steering CO₂ hydrogenation toward C-C coupling to hydrocarbons using porous organic polymer/metal interfaces

The conversion of CO₂ into fuels and chemicals is an attractive option for mitigating CO₂ emissions. Controlling the selectivity of this process is beneficial to produce desirable liquid fuels, but C-C coupling is a limiting step in the reaction that requires high pressures. Here, we propose a strategy to favor C-C coupling on a supported Ru/TiO₂ catalyst by encapsulating it within the polymer layers of an imine-based porous organic polymer that controls its selectivity. Such polymer confinement modifies the CO₂ hydrogenation behavior of the Ru surface, significantly enhancing the C₂₊ production turnover frequency by 10-fold. We demonstrate that the polymer layers affect the adsorption of reactants and intermediates while being stable under the demanding reaction conditions. Our findings highlight the promising opportunity of using polymer/metal interfaces for the rational engineering of active sites and as a general tool for controlling selective transformations in supported catalyst systems.