Dry Reforming of Methane on Low-Loading Rh Catalysts

Abstract

Dry reforming of methane (DRM) is a promising catalytic process for converting greenhouse gases (CH₄ and CO₂) into syngas (CO and H₂). This study investigates DRM under moderate conditions (550 °C) using supported low-loading (0.05 wt%) metal (M) catalysts (M = Rh, Ru, Pt, Pd, Ir, Au, and Ni). The reaction was carried out for 6 h with a flow rate of 30 mL/min for both CH₄ and CO₂, using 0.10 g of catalyst. Among these catalysts, 0.05 wt% Rh/Al₂O₃ exhibited the highest DRM activity. The effect of catalyst supports revealed that Al₂O₃ is the most effective support for 0.05 wt% Rh. The DRM activity of Rh species supported on Al₂O₃ and SiO₂ was compared, and the Rh species on Al₂O₃ outperformed those on SiO₂, indicating Al₂O₃ enhances the DRM activity of Rh. When comparing the DRM activity of Rh nanoparticles and Rh single atoms, it was suggested that Rh nanoparticles might exhibit superior performance for DRM. Coke deposited on 0.05 wt% Rh/Al₂O₃ is removed by CO₂, maintaining stable catalytic activity. These findings provide valuable insights into the design of catalysts that minimize the use of noble metals in DRM reactions.