Rh/Al Nanoantenna Photothermal Catalyst for Wide-Spectrum Solar-Driven CO2 Methanation with Nearly 100% Selectivity

Solar-powered CO 2 conversion represents a promising green and sustainable approach for achieving a carbon-neutral economy. However, the rational design of a wide-spectrum sunlight-driven catalysis system for effective CO 2 reduction is an ongoing challenge. Herein, we report the preparation of a rhodium/aluminum (Rh/Al) nanoantenna photothermal catalyst that can utilize a broad range of sunlight (from ultraviolet to the near-infrared region) for highly efficient CO 2 methanation, achieving a high CH 4 selectivity of nearly 100% and an unprecedented CH 4 productivity of 550 mmol·g –1 ·h –1 under concentrated simulated solar irradiation (11.3 W·cm –2 ). Detailed control experiment results verified that the CO 2 methanation process was facilitated by the localized surface plasmonic resonance and nanoantenna effects of the Rh/Al nanostructure under light irradiation. In operando temperature-programmed Fourier transform infrared spectroscopy confirmed that CO 2 methanation on the Rh/Al nanoantenna catalyst was a multistep reaction with CO as a key intermediate. The design of a wide-spectrum solar-driven photothermal catalyst provides a feasible strategy for boosting CO 2 -to-fuel conversion.