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 center dot 6Al(2)O(3), BHA) with high surface area (BHA-HSA) (>100 m(2) 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 degrees 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 degrees C and 3.0 MPa, and a lifetime test shows that, at 500 degrees 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.