Catalytic decomposition of ammonia in simulated coal-derived gas

Alumina-supported Ni and/or Ru catalysts were prepared and their ability to decompose ammonia in simulated coal-derived gas fuel from 250 to 900 °C using a conventional fixed-bed flow reactor at atmospheric and high pressure (0.9 MPa) was tested. The surface properties of the catalysts were investigated using BET, CO chemisorption, XRD, and TPD after NH3NH3 adsorption. Supported Ni catalyst promoted NH3NH3 decomposition to N2N2 above 700 °C with and without oxygen addition in the fuel. Supported Ni catalyst had the potential to decompose NH3NH3 to N2N2 from 400 to 550 °C with the addition of a small amount of oxygen in the fuel, while the addition of Ru significantly reduced the potential. Ni selectively promotes NH3NH3 oxidation to N2N2 at low temperature, while Ru selectively promotes H2H2 oxidation to H2OH2O.