Template preparation of high-surface-area barium hexaaluminate as nickel catalyst support for improved CO methanation

Abstract

We report the simple preparation of the barium hexaaluminate (BaO·6Al₂O₃, BHA) with high surface area (BHA-HSA) (>100 m² g⁻¹) through a coprecipitation method using carbon black as the hard template. Ni catalysts supported on BHA-HSA (Ni/BHA-HSA) with different NiO loadings (10, 20, and 40 wt%) were investigated in CO methanation for the production of synthetic natural gas (SNG). The CO methanation reaction was carried out at 0.1 and 3.0 MPa with a weight hourly space velocity of 30 000 mL g⁻¹ h⁻¹. It was found that Ni/BHA-HSA catalysts showed increased activity at low temperature (240–400 °C) compared with more conventional Ni/BHA catalysts with the same NiO loadings. A highest CH₄ yield of 95.7% can be obtained over Ni/BHA-HSA (40 wt% of NiO loading) at 400 °C and 3.0 MPa, and a lifetime test shows that, at 500 °C and 3.0 MPa, it is more stable than Ni/BHA. The serious aggregation of Ni nanoparticles is the major reason for the deactivation of the latter. The work demonstrates that BHA-HSA can be effectively prepared using carbon black as the hard template and is more suitable as a Ni catalyst support for CO methanation.