Steam reforming of glycerol for co-producing hydrogen and carbon nanotubes over nanoscale Ni-based catalysts: Insights into support effect and carbon deposition

Glycerol, a major byproduct of biodiesel production, is commonly used as an inexpensive feedstock for hydrogen (H 2 ) production through catalytic reforming. Developing efficient Ni-based catalysts with appropriate supports remains a challenge. In this study, three Ni-based catalysts, each containing 10 wt% Ni with different supports: carbon nanofibers (Ni@CNF), activated carbon (Ni/AC), and alumina (Ni/γ-Al 2 O 3 ), were comparatively evaluated for their effectiveness in the catalytic steam reforming of glycerol. The results show that both the catalyst support and the reforming temperature influence the co-production of H 2 and carbon nanotubes. All three catalysts exhibit good catalytic performance of H 2 production at 700 °C for 1 h. The corresponding H 2 yields, based on a steam-glycerol molar ratio of 11.9 and a flow rate of 0.2 mL/min, are 86.5%, 81.3%, and 69.2% for Ni@CNF, Ni/AC, and Ni/Al 2 O 3 , respectively. Ni@CNF demonstrates high H 2 production and good catalytic stability, whereas Ni/Al 2 O 3 generates high-yield carbon nanotubes.