Precipitation of Ni nanoparticle on Al₂O₃ powders by novel rotary chemical vapor deposition

Ni nanoparticles were precipitated on Al₂O₃ support powder by rotary chemical vapor deposition (RCVD). The Ni nanoparticle size increased from 8 to 62nm in diameter and the content of Ni decreased from 6.6 to 2.4mass % with increasing Al₂O₃ powder diameter (D _Al2O3) from 80nm to 150 μm. The catalytic activity of Ni precipitated Al₂O₃ (Ni/Al₂O₃) powder was evaluated by the hydrogen production rate (R_H2) in a methanol-steam flow. The R_H2 decreased with increasing D _Al2O3 and increased with increasing specific surface area of Ni/Al₂O₃ powder. The highest R_H2 of Ni/Al ₂O₃ powder was 709 × 10^-3 mol kg ^-1 s^-1 at 633 K, D_Ni = 8nm and D _Al2O3 = 80nm.