Achieving Stable Syngas Production during Photothermal synergistic Dry Reforming of Methane over Layered Double Hydroxides-Based Catalysts with anti-coking Performance

Abstract

Dry reforming of methane (DRM) offers a promising route to convert CH 4 and CO 2 into syngas, addressing both greenhouse gas mitigation and carbon resource utilization. However, its practical application is hindered by high energy consumption and severe catalyst deactivation due to coking. Leveraging the structural tunability of layered double hydroxides (LDH), we synthesized three LDH-derived spinel-supported Ni-based catalysts (Ni/XAl 2 O 4 , X = Mg, Co, Cu) and evaluated them in photothermal synergistic catalytic DRM (PTSC-DRM). Substituting Cu with Mg in the support markedly increased the specific surface area from 44.81 to 181.29 m 2 •g -1 , significantly enhanced CO 2 adsorption capacity, and strengthened the metal-support interactions.Under 600 °C and 2.91 W•cm -2 illumination, Ni/MgAl 2 O 4 achieved CH 4 and CO 2 conversions of 38.49% and 42.13%, respectively, and maintained stable performance over 45.5 h of continuous operation. The coking rate was drastically reduced from 5.00 mgCwith no reactor clogging observed. Mechanistically, light irradiation continuously promotes CO 2 activation through photogenerated electron-hole pairs, synergistically enhancing coking resistance alongside the thermal catalytic pathway. This work capitalizes on the structural versatility of LDH materials and provides a new strategy for designing low-cost, highstability, and coke-resistant catalysts for PTSC-DRM.