Photothermal dry reforming of methane reaction over (Ni/Ce_0.8Zr_0.2O₂)@SiO₂ catalysts: The Ni content regulation

Dry reforming of methane (DRM) converts CH₄ and CO₂ to syngas. Photothermal DRM, which integrates temperature and light, is a sustainable method for storing solar energy in molecules. However, challenges such as limited light absorption, low photocarrier separation efficiency, Ni sintering, and carbon deposition hinder DRM stability. Herein, we regulated Ni contents in (Ni/Ce_0.8Zr_0.2O₂)@SiO₂ catalysts to enhance the optical characteristics while addressing Ni sintering and carbon deposition issues. The (3Ni/Ce_0.8Zr_0.2O₂)@SiO₂ catalyst had insufficient Ni content, while the (9Ni/Ce_0.8Zr_0.2O₂)@SiO₂ catalyst showed excessive carbon deposition, leading to lower stability compared to the (6Ni/Ce_0.8Zr_0.2O₂)@SiO₂ catalyst, which achieved CH₄ and CO₂ rates to 231.0 μmol/(g_cat·s) and 294.3 μmol/(g_cat·s), respectively, at 973 K, with only 0.2 wt.% carbon deposition and no Ni sintering. This work adjusted Ni contents in (Ni/Ce_0.8Zr_0.2O₂)@SiO₂ catalysts to enhance DRM performance, which has implications for improving other reactions.