Photothermal dry reforming of methane reaction over (Ni/Ce0.8Zr0.2O2)@SiO2 catalysts: The Ni content regulation

Dry reforming of methane (DRM) converts CH 4 and CO 2 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 0.8 Zr 0.2 O 2 )@SiO 2 catalysts to enhance the optical characteristics while addressing Ni sintering and carbon deposition issues. The (3Ni/Ce 0.8 Zr 0.2 O 2 )@SiO 2 catalyst had insufficient Ni content, while the (9Ni/Ce 0.8 Zr 0.2 O 2 )@SiO 2 catalyst showed excessive carbon deposition, leading to lower stability compared to the (6Ni/Ce 0.8 Zr 0.2 O 2 )@SiO 2 catalyst, which achieved CH 4 and CO 2 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 0.8 Zr 0.2 O 2 )@SiO 2 catalysts to enhance DRM performance, which has implications for improving other reactions. Photothermal DRM performance was dependent on Ni content in the (Ni/Ce 0.8 Zr 0.2 O 2 )@SiO 2 catalysts. The optimized (6Ni/Ce 0.8 Zr 0.2 O 2 )@SiO 2 reached the highest DRM rate compared to other investigated catalysts, resolving Ni sintering and carbon deposition by the synergetic contributions from metal-support interaction and confinement effect. • (Ni/Ce 0.8 Zr 0.2 O 2 )@SiO 2 with Ni contents of 3, 6 and 9 wt.% are investigated for photothermal DRM. • (Ni/Ce 0.8 Zr 0.2 O 2 )@SiO 2 catalysts have high capacities to adsorb light. • SiO 2 confinement and Ni-Ce 0.8 Zr 0.2 O 2 interaction ensure non-sintering of Ni nanoparticles. • Light irradiation accelerated gasification of carbon precursors. • Synergism between light and temperature promotes DRM performance.