Driving catalysts to the intrinsic optical selectivity limit for accelerating photothermal catalysis

Optimizing the photothermal conversion (maximized solar absorption, minimized mid-infrared emissivity) and catalytic activity is essential for constructing highly efficient photothermal catalysts. However, most catalysts lack intrinsic optical selectivity (i.e., high αsolar and low εMIR) and fail to suppress εMIR, which significantly compromises their catalytic performance. Herein, we propose an optical depth strategy to drive catalysts to their intrinsic optical selectivity limit. Demonstrated in metal oxides, this approach simultaneously maximizes αsolar and minimizes εMIR without compromising intrinsic catalytic activity. Demonstrated in the photothermal Sabatier and Bosch processes, our strategy increases methane production by ~590% and carbon nanotube yield by ~200%. Notably, the optimized Co2.85Ru0.15O4 optically selective catalyst exhibits a ~ 26.7% increase in photothermal conversion efficiency. This enhancement leads to a record CH4 production rate of 3375.5 mmol gcat−1 h−1 at a light intensity of 2.8 W cm−2. This innovative strategy highlights the prospects for achieving intrinsic optical selectivity in photothermal catalysts. Optimizing photothermal conversion and catalytic activity is crucial for developing highly efficient photothermal catalysts. Here, the authors propose an optical-depth strategy to drive catalysts toward their intrinsic optical selectivity limit, thereby enhancing the efficiency of photothermal catalysis.