In situ magnetometer study on the formation and stability of cobalt carbide in Fischer–Tropsch synthesis

Role of Co2C in ZnO‐promoted Co Catalysts for Alcohol Synthesis from Syngas

“…The Co 2 C catalysts decomposed at 250 °C in H 2 . This result agrees with prior work showing that temperatures below 200 °C are high enough to decompose Co 2 C in H 2 ,. Upon decomposition, the Co 2 C catalyst formed hcp ‐Co ,.…”

“…Furthermore, recent studies have noted that there is already a high coverage of C species on Co during syngas conversion, and our ex situ XPS data of the spent Co catalyst agrees with this. Next, we note that prior work has found Co 2 C catalysts to be stable in syngas for extended periods, and we calculated that Co 2 C is stable relative to fcc ‐Co by 1.2 eV on a per unit cell basis at the conditions used in this study. Since Co 2 C is thermodynamically favorable, we conclude that there must be a kinetic limitation to its formation.…”

On the superior activity and selectivity of PtCo/Nb2O5 Fischer Tropsch catalysts

“…Upon Ptpromotion of Co/c-Al 2 O 3 , TOF app at 20 bar was calculated to decrease, whereas it remained unchanged in Fischer Tropsch synthesis at low pressure (SI, Table S2). The reason might be related to incomplete reduction of Co/c-Al 2 O 3 during H 2 chemisorption experiments and consequent overestimation of TOF app after further reduction during Fischer Tropsch synthesis [51]. Upon Ptpromotion of Co/Nb 2 O 5 , TOF app was calculated to increase by a factor of 1.8 (20 bar, Table 2) to 2.2 (1 bar, SI, Table S2).…”

Reflections on the Fischer-Tropsch synthesis: Mechanistic issues from a surface science perspective

“…Although in this light we cannot exclude that C hydrogenation and subsequent transfer of CH x form the slowest step, we can look at experimental data obtained on supported Co catalysts to gain more insight into the hydrogenation of carbon. Literature reports indicate that hydrogenation of cobalt carbide proceeds around FT synthesis temperatures [48,49]. The previously discussed study by Yang et al [46] also provides information on the reactivity of surface carbon formed during methanation.…”