Boosted photothermal synergistic CO₂ methanation over Ru doped Ni/ZrO₂ catalyst: From experimental to DFT studies

The hydrogenation of CO₂ to CH₄ presents a captivating and challenging avenue for CO₂ reutilization. In this study, we explored the potential of photo-thermal catalytic (PTC) reactions for CO₂ conversion to CH₄. Herein, we employed a novel catalyst, NiRu/ZrO₂, for photothermal CO₂ methanation. Remarkably, the Ru-doped Ni/ZrO₂ catalyst demonstrated significantly higher catalytic activity compared to the Ni monometallic catalyst. The optimized Ru doping conditions led to decreased temperature requirements and promoted CO₂ conversion rates, achieving an impressive 100% CH₄ selectivity. Detailed characterizations of the catalyst revealed several advantageous properties of NiRu/ZrO₂, including superior optical absorption performance, a higher temperature of CO₂ resolved peak, and an increased binding energy of the Ni²⁺ peak. Furthermore, density functional theory (DFT) calculations demonstrated that the addition of Ru positively influenced CO₂ adsorption, thereby lowering the energy barrier for CO₂ decomposition and C species hydrogenation. This research sheds light on the potential of the Ru-doped Ni/ZrO₂ catalyst for efficient CO₂ conversion to CH₄ through photothermal catalysis. These findings offer valuable insights for the development of advanced catalysts in CO₂ reutilization strategies.