Layered Na₂Ti₃O₇-supported Ru catalyst for ambient CO₂ methanation.

Abstract

The methanation of CO₂ offers a practical solution for storing renewable energy and mitigating global climate risks. However, the primary challenge lies in achieving efficient CH₄ production at lower temperatures. Here, we report a layered Na₂Ti₃O₇-supported Ru catalyst as a stabilizer of low-valence Ru that enables CO₂ activation at low temperatures. This catalyst leads to a CH₄ production rate of 33.6 and 139.1 mmol g_cat^-1 h^-1 at 140 and 180 °C, respectively, with a gas hourly space velocity of 24,000 mL g^-1 h^-¹ at ambient pressure (1 bar), significantly surpassing state-of-the-art catalysts performance. Moreover, the catalyst demonstrates robustness to on-off intermittency and 220-hour long-term stability tests, indicating its reliability under challenging conditions. The catalyst is also successfully synthesized at the gram scale and on a 3D-printed metal self-catalytic reactor by a facile ion-exchange method, confirming its excellent scalability. This study marks a significant step forward in the design of catalysts for the low temperature CO₂ hydrogenation.