Unveiling the Synergistic Effect of Bimetallic Doping and Lattice Strain on Photothermal Catalytic Performance for CO ₂ Methanation

Lattice strain engineering induced by heteroatom doping serves as an effective approach to precisely regulate the electronic structure and enhance the intrinsic activity of catalysts. However, the synergistic role of bimetallic co‐doping in steering the strain effect and its impact on the catalytic performance remains to be explored. Herein, we introduced Ni and Ru co‐doping in barium titanate (Ba 0.9 Ti 0.8 Ni 0.1 Ru 0.1 O 3‐δ , BTNR22) with the lattice expansion strain, where Ni serves to induce lattice strain, and Ru stabilizes the crystal structure and modulates the electronic structure of active sites. The porous BTNR22 catalyst exhibits enhanced performance for photothermal CO 2 methanation, with a CH 4 evolution rate of 126.93 mmol·g −1 ·h −1 at 400°C, 373 times higher than that of Ba 0.9 TiO 3‐δ . In addition, the in situ diffuse reflectance infrared Fourier‐transform spectroscopy (in situ DRIFTS) and density functional theory (DFT) calculations reveal that the lattice expansion strain narrowed the bandgap of the catalyst, and the Ru‐V O active sites facilitated the thermodynamically favorable pathway, synergistically enhancing the adsorption and activation of CO 2 and the photogenerated carrier dynamics. This study offers a promising avenue for constructing highly active catalysts via strain engineering and mechanistic insight into the correlation between photothermal catalysis and the strain effect.