Bifunctional catalysts derived from mineral ores for cost-effective and robust CO2 capture and conversion

The development of cost-effective and efficient bifunctional materials is crucial for advancing integrated CO₂ capture and utilization (ICCU) technologies. Herein, we report the rational design of a cost-effective bifunctional composite, Ni nanoparticles dispersed on KNaTiO₃ (denoted as KR3) for CO₂ sorption and hydrogenation to CO. The KR3 derived from low-cost natural rutile sand was responsible for CO₂ sorption, while the uniformly dispersed nickel nanoparticles facilitated the transformation of sorbed CO₂ to CO. The formed bifunctional materials showed a CO₂ conversion of 76.7 % with near-perfect selectivity towards CO, and robust cyclic stability over 10 cycles. Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) analysis revealed both the redox mechanism and formate reaction pathway existed in CO₂ hydrogenation to CO. The pelletized 10Ni/KR3 still exhibited decent CO₂ sorption capacity in the presence of O₂, and 84 % retention of CO₂ conversion was achieved in the hydrogenation process. The bifunctional 10Ni/KR3 material, distinguished by its high CO₂ sorption capacity, superior conversion activity, and robust cyclic stability, not only provides crucial insights for advancing solid CO₂ sorbents for flue gas capture and conversion but also demonstrates significant potential for practical carbon mitigation.