Enhanced photothermal methane dry reforming through electronic interactions between nickel and yttrium†

Abstract

Dry reforming of methane (DRM) is a promising technology for converting greenhouse gases (CH₄ and CO₂) into syngas. However, the traditional thermal catalytic process requires high temperature, resulting in low selectivity, and coke-induced instability. In this study, a Y-doped nickel-based photothermal catalyst, NiY/fibrous nano-silica (KCC-1), was obtained for the DRM reaction, exhibiting excellent photothermal catalytic DRM activity with a CO yield rate of above 90.01 mmol g⁻¹ h⁻¹ at 450 °C. The spatial confinement effect of KCC-1 enhanced the catalyst stability, maintaining fresh activity for up to 40 hours. Various characterization techniques reveal that strong d-electron transfer from Y to Ni is beneficial for preserving metallic Ni, which in turn promotes the adsorption and activation of CH₄. In situ DRIFTS and DFT theoretical studies further elucidate the mechanism that the Y-doped strategy not only facilitates the adsorption and activation of CO₂ (due to the strong basicity of Y₂O₃) but also enhances the photothermal effect by facilitating the formation of metallic Ni⁰, resulting in a greater generation of p-CO₃²⁻ intermediates to achieve excellent photothermal catalytic performance. The findings of this study are expected to provide a rare earth metal doping strategy for designing highly efficient photothermal catalysts for the synthesis of solar fuel.