Molybdenum carbide catalysts I. Synthesis of unsupported powders

Temperature-programmed reaction between MoO3 of low specific surface area Sg and a CH4H2 mixture produces unsupported powders of hexagonal Mo2C with Sg from 50 to 100 m2 g− and CO uptake number density of up to 5.0 × 1014 cm−2. Depending on the preparation conditions, this material can be synthesized with a surface free of contamination by noncarbidic carbon (Mo2C-I) or with a surface completely covered by polymeric carbon layers (C-Mo2C). For the latter case a method of treatment with dihydrogen was developed that removes the carbon contamination to create an active carbide surface (Mo2C-lI).