Metal oxide‐doped Ni/CaO dual‐function materials for integrated CO2 capture and conversion: Performance and mechanism

Abstract Integrated CO 2 capture and conversion (ICCC) into valuable chemicals such as CH 4 and CO is a promising approach to mitigate anthropogenic CO 2 emissions. In this work, we prepared a series of metal oxide (M x O y , M = Mg, Al, Mn, Y, Zr, La, and Ce)‐doped Ni/CaO dual‐function materials (DFMs) and applied them to the ICCC process. The property–performance relationship of the DFMs was studied, and the conversion mechanism of the captured CO 2 was explored. For any DFM at any ICCC cycle (20 cycles in total), the CO 2 captured at the carbonation stage was completely released as CH 4 , CO, and CO 2 at the conversion stage. Among all DFMs, Ni/CaZr(O) showed the best ICCC performance because of its good thermal stability. The conversion of captured CO 2 on the DFMs proceeded via a two‐step mechanism, where CO 2 was first released from CaCO 3 and then converted into CH 4 at Ni sites and CO at CaO sites.