Improved methanation catalysts

Abstract

New procedures have been developed for preparation of improved methanation catalysts. Supported metal catalysts have been prepared, starting with controlled solidification (undirectional or gas atomization) of eutectic or proeutectic alloys of transition metals (rhodium and nickel) and aluminium, followed by chemical dissolution in caustic of the aluminum component and acid precipitation of the aluminum as alumina to provide a high surface area oxide matrix for the dispersed catalytically active rhodium (0.36 w/o) or nickel (6.1 w/o). Unsupported skeletal nickel catalysts have been produced by gas atomization and rotary atomization techniques from proeutectic nickel (28.6 w/o Ni) aluminum alloy powders by caustic activation. Characterization of the supported and unsupported catalysts by x‐ray diffraction, electron microscopy, BET nitrogen adsorption and hydrogen chemisorption demonstrated that the activated metals, rhodium and nickel, were in a highly dispersed state and, in the case of the alumina supported catalysts, present on a high surface area stabilized substrate. The superior surface physical properties, pore structure, total surface areas and available metal surface areas, and the superior initial catalytic activity of these experimental catalysts compared with more conventional rhodium and nickel supported and RaneyR catalysts establish the merits of controlled solidification procedures as a new path for synthesis of methanation catalysts.