Combined Methane Cracking for H₂ Production with CO₂ Utilization for Catalyst Regeneration Using Dual Functional Nanostructured Particles

Abstract

A two-stage chemical looping approach is demonstrated for sustainable hydrogen production through methane decomposition (CH 4 → C + 2H 2 ) combined with cyclic catalyst regeneration via the reverse Boudouard reaction (C + CO 2 → 2CO). A Nibased spherical nanoparticle cluster, fabricated using a continuous aerosol-based synthetic approach, is developed for effective cyclic catalysis of the above two chemical reactions. A sufficiently high CO 2 conversion rate for catalyst regeneration (in terms of TOF CO 2 , 36.09 h −1 ) and a stably high yield of hydrogen (in terms of STY H 2 , 5.19 mmol g cat −1 min −1 ) are achievable using the 10Ni−1Ce/5Al sample. The outstanding performance of 10Ni−1Ce/ 5Al is attributed to the incorporation of CeO 2 as a promoter, which possesses a high redox ability that enhances catalytic activity.Additionally, the synergistic effect between nickel and ceria on the two-stage chemical looping is of crucial importance, where CeO 2 promotes CO 2 capture and Ni catalyzes CO 2 dissociation at the Ni−CeO 2 interface. CeO 2 -incorporated samples generating whisker carbon after methane pyrolysis demonstrate better activity for cyclic catalyst regeneration. The novelty of the work stands on developing a high-performance dual functional nanostructured catalyst using an aerosol-based synthetic route. This approach creates a massive amount of active interface, by which the two-stage reactions can be promoted under a remarkably low temperature (e.g., 600 °C). The proposed dual functional catalyst material and catalytic pathway demonstrate significant advances for effective hydrogen production combined with cyclic catalyst regeneration via CO 2 utilization, offering an eco-friendly pathway for industrial applications.