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.