MOF-derived Ni-Ir/CeO₂@SiO₂ catalyst with full spectrum utilization ability for anti-coking photothermal dry reforming of methane

Photothermal synergistic catalysis for dry reforming of methane (PTSC-DRM) has garnered attention for its ability to efficiently convert CH₄ and CO₂ into syngas by coupling thermal and renewable solar energy. A critical challenge in this field is the development of catalysts that achieve both full-spectrum utilization and excellent anti-coking performance. This study presents a Ni-Ir/CeO₂@SiO₂ catalyst derived from a metal-organic framework (MOF). By loading a well-dispersed Ni-Ir bimetallic alloy onto MOF-derived CeO₂, we achieved synergistic activation of CO₂ and CH₄, while the SiO₂ shell enhanced full solar spectrum utilization. Under PTSC conditions at 650 °C, this catalyst exhibited CO₂ and CH₄ conversion of 80.9 % and 74.8 %, respectively. After continuous operation at 600 °C for 180 h, it maintained a very low coking amount of 3.21 % (coking rate of 0.178 mgC·g_cat⁻¹·h⁻¹). Characterization results, including PL, indicated that the Ni-Ir/CeO₂@SiO₂ catalyst features a significantly optimized band gap structure (2.01 eV) and improved photogenerated electron lifetime. CO₂-TPD and XPS analyses revealed the synergistic effect of the Ni-Ir bimetal to enhance CO₂ activation and coking resistance. This research provides innovative structural design concepts and theoretical support for developing PTSC-DRM catalysts with high activity, anti-coking properties, and full-spectrum solar energy utilization.