Molybdenum carbide catalysts: I. Synthesis of unsupported powders

Abstract

Temperature-programmed reaction between MoO 3 of low specific surface area S g and a CH 4 H 2 mixture produces unsupported powders of hexagonal Mo 2C with S g from 50 to 100 m 2 g − and CO uptake number density of up to 5.0 × 10 14 cm −2. Depending on the preparation conditions, this material can be synthesized with a surface free of contamination by noncarbidic carbon (Mo 2C-I) or with a surface completely covered by polymeric carbon layers (C-Mo 2C). For the latter case a method of treatment with dihydrogen was developed that removes the carbon contamination to create an active carbide surface (Mo 2C-lI).