Methanol Conversion on Ni/SiO2 and Ni/Al2O3 Catalysts

Abstract

The relationship between activity for catalytic conversion of methanol and the properties of Ni/SiO2 and Ni/Al2O3 catalysts was studied. Syngas (2H2+CO) was selectively produced by both catalysts up to the point at which ca. 87% of the input methanol was converted. As the reaction temperature was increased, methane was synthesized from the syngas produced by methanol conversion. This reaction was followed very closely by the shift reaction which yielded CO2 and H2 from the reaction of CO from the syngas and H2O, the byproduct of the methane formation reaction. The apparent activation energy for formation of H2 was 15kcal/mol for Ni/SiO2 and Ni/Al2O3 with Ni loading greater than 5wt%. When Ni was less than 3wt%, the catalytic activity of the Ni on the alumina support was considerably weakened by strong metal-support interactions, and the dimethyl ether formation on the acidic sites of the alumina support predominated over the syngas formation. Lanthanum oxide added to the Ni/Al2O3 catalyst suppressed the dimethyl ether formation with a resulting increase in the yield of H2. In the case of Ni/SiO2 catalyst, however, no metal-support interaction nor dimethyl ether formation was observed, and the lanthanum oxide did not affect the catalytic activity. © 1983, The Japan Petroleum Institute. All rights reserved.