Borided metal catalysts in methanation of carbon monoxide: I. Initial activity and conversion-temperature behavior of unsupported catalysts

Abstract

Unsupported metal borides were prepared by reduction at 273–300 K of NiII and CoII by sodium borohydride in aqueous and ethanolic solvents in the presence and absence of noble metal promoters. These materials were further activated by H2 reduction at 675–725 K which resulted generally in borided metals having higher metal: boron ratios than commonly encountered in the chemically reduced materials. Chemical, physical, and catalytic properties were determined by chemical analysis, BET surface area measurements, H2 adsorption measurements, and reactor studies of methanation activity/selectivity properties at 1 atm and 475–675 K. Though generally slightly less active and selective than commercial Raney nickel, borided nickel catalysts are nevertheless very effective methanation catalysts compared to pure nickel. Borided cobalt is apparently as active as Raney nickel on a site basis but less selective for CH4 production. Ruthenium- and rhodium-promoted nickel borides are slightly more active and about as selective for methane production as unsupported nickel. © 1980, All rights reserved.