Active Exsolved Metal–Oxide Interfaces in Porous Single‐Crystalline Ceria Monoliths for Efficient and Durable CH 4 /CO 2 Reforming

Dry reforming of CH 4 /CO 2 provides an attractive route to convert greenhouse gas into syngas; however, the resistance to sintering and coking of catalyst remains a fundamental challenge at high operation temperatures. Here we create active and durable metal–oxide interfaces in porous single‐crystalline (PSC) CeO 2 monoliths with in situ exsolved single‐crystalline (SC) Ni particles and show efficient dry reforming of CH 4 /CO 2 at temperatures as low as 450 °C. We show the excellent and durable performance with ≈20 % of CH 4 conversion and ≈30 % of CO 2 conversion even in a continuous operation of 240 hours. The well‐defined active metal–oxide interfaces, created by exsolving SC Ni nanoparticles from PSC Ni x Ce 1− x O 2 to anchor them on PSC CeO 2 scaffolds, prevent nanoparticle sintering and enhance the coking resistance due to the stronger metal–support interactions. Our work would enable an industrially and economically viable path for carbon reclamation, and the technique of creating active and durable metal–oxide interfaces in PSC monoliths could lead to stable catalyst designs for many challenging reactions.