The influence of mass transfer conditions on the stability of molybdenum carbide for dry methane reforming

Stability of supported and promoted-molybdenum carbide catalysts in dry-methane reforming

“…Analogous conclusions have been drawn by other researchers, and several studies have focused on the oxidative stability of Mo 2 C under reforming conditions [1][2][3][4]. Oxidation of Mo 2 C during reforming has been found to be preventable by operating the reformer at higher pressures [1,2] or at atmospheric pressure under either back-mix conditions [3] or temperatures in excess of 950 8C [4].…”

“…Furthermore, LaMont and Thomson [4] found that the stability of Mo 2 C during DMR was related to the mass transfer of reforming product gases (CO + H 2 ) from the surface of the catalyst. Under mass transfer limited conditions, such as high pressure, high temperature and low molar feed velocities, oxidation of Mo 2 C to form MoO 2 could be prevented [4]. These observations also explain the stability of Mo 2 C at high pressure formerly proposed by York et al [1].…”

“…Molybdenum carbide (Mo 2 C) has been studied as a catalyst for steam methane reforming (SMR) [1,2], dry-methane reforming (DMR) [1][2][3][4][5] and partial oxidation of methane (POM) [6], with the majority of the studies having been carried out over unsupported Mo 2 C. The first study conducted by York et al [1] found that these catalysts possessed reforming activity comparable to noble metals while being less susceptible to coking than nickel, but deactivated via oxidation of Mo 2 C to inactive MoO 2 . Analogous conclusions have been drawn by other researchers, and several studies have focused on the oxidative stability of Mo 2 C under reforming conditions [1][2][3][4].…”

Sulfur Tolerance of Carbide Catalysts Under Hydrocarbon Reforming Conditions

“…They attributed this to competitive kinetics between oxidation and carburization, concluding that carburization kinetics were more favorable at higher pressures. We have determined that higher pressures lower the mass transfer rates between the catalyst surface and the bulk gas [4]. This has the effect of maintaining higher concentrations of the reforming product gases at the catalyst surface, thereby protecting the surface from oxidation.…”

The effect of lanthanum addition on the catalytic activity of γ-alumina supported bimetallic Co–Mo carbides for dry methane reforming

“…In particular, monometallic molybdenum carbide, Mo 2 C, has been tested as a catalyst for a number of reactions, including SMR [7], DMR [8,9,21,26], POM [36] and hydrotreating [37]. The use of supported metal carbides was also considered in an attempt to further improve catalytic activity and stability of these materials.…”