Ni-phyllosilicate structure derived Ni–SiO2–MgO catalysts for bi-reforming applications: acidity, basicity and thermal stability

Abstract

In this work, Ni–SiO₂–MgO materials synthesized via Ni-phyllosilicate (PS) intermediates were explored for bi-reforming of methane (BRM) reaction. The influence of steam and reaction temperature was also investigated for the BRM reaction. Overall, the 15 wt% Ni–30 wt% SiO₂–55 wt% MgO (Ni–SiO₂–MgO[55]) catalyst maintained exceptional catalytic performance (CH₄ and CO₂ conversions were 80% and 60%, respectively) at 750 °C for 140 h with negligible carbon deposition and also showed a stable H₂/CO of 2.0. The best catalytic performance of the Ni–SiO₂–MgO[55] catalyst is attributed to its enhanced basicity strength, reasonable moderate acidity strength and structural stability during high temperature reforming reaction. The formation and presence of Ni–Mg-containing phyllosilicates in fresh and reduced catalysts respectively was confirmed by TEM images and XRD analysis. The T_max of around 750 °C in TPR profiles of Ni/SiO₂–MgO catalysts further confirms the strength of interactions between Ni and SiO₂–MgO support species.