Self-optimized Ni-MnOx interactions tailor H recombination activity for enhanced integrated CO2 capture and super dry reforming of methane with H2-free CO production

Integrated carbon capture and utilization via dry reforming of methane (ICCU-DRM) paves a sustainable way for directly converting CO 2 from flue gas into CO. However, the process suffers from severe carbon depositions and low CH 4 utilization. Herein, we demonstrate that the NiMnxCa dual functional materials undergo a spontaneous structural self-optimization during cyclic ICCU-DRM process. The MnO x can segregate from (MnO) α (CaO) 1-α solid solution during CO 2 capture. Consequently, the Ni-MnO x interaction, with a MnO x -coated Ni surface, can be intensified with the material reconstruction, which effectively suppresses the hydrogen recombination probability and prevent carbon deposition. Moreover, the *H from CH 4 activation can react with MnO, enabling highly efficient conversion of CO 2 via in situ chemical looping pathway. As an example, the NiMn5Ca achieved a ~ 100 % H utilization (~ 0 H 2 production), 95 % CO 2 conversion and < 1 carbon deposition/per mol of converted CO 2 at 675 °C in 25 cycles. The work illustrates a typical scenario of an intelligent structure optimization under reaction environment and proposes a strategy to enhance CH 4 utilization efficiency by directing *H to a fast surface reaction rather than desorbing as H 2 .