ChemInform Abstract: Structural Characterization of Cobalt Catalysts on a Silica Support

Abstract

is performed by in situ XRD during H2 reduction at 350 °C, (16 h) of catalysts with various Co loadings prepared by different methods.

Combined Operando X‐ray Diffraction/Raman Spectroscopy of Catalytic Solids in the Laboratory: The Co/TiO2 Fischer–Tropsch Synthesis Catalyst Showcase

“…The two‐step reduction behavior of supported Co/TiO 2 catalysts that we have seen for this catalyst has previously been demonstrated by using temperature‐programmed reduction (TPR) and XANES spectroscopy . Also the mixture of the HCP and CCP crystal structures upon reduction of supported Co catalysts has been observed before …”

The structure modification and activity improvement of Pd–Co/C electrocatalysts by the addition of Au for the oxygen reduction reaction

“…1a 1. 44 As shown in Table 1, the X Au is higher than X Co (52.6% vs. 8.9%), indicating that Pd-Au alloys can be formed at the low reduction temperature of 390 K. On the other hand, the low X Co for Au 0 is ascribed to the insufficient reduction temperature for Co precursors since the temperature for complete reduction of Co is at least 620 K. 45 Despite Au 0 has the low X Co , our previous studies suggest that a high reduction temperature results in the serious agglomeration of Pd-Co alloy NPs together with Co surface enrichment and the concomitant decline in ORR activity. 32,33 On the other hand, for the XRD patterns of Au 5 (Pd 75 Co 20 Au 5 /C) and Au 15 (Pd 75 Co 10 Au 15 /C) catalysts, their major diffraction (111) peaks lie between those of the Au 0 and Au 25 ones, suggesting that these two samples may be concurrently comprised of Pd-Co and Pd-Au alloys.…”

X-ray absorption, X-ray diffraction and electron microscopy study of spent cobalt based catalyst in semi-commercial scale Fischer–Tropsch synthesis

“…Regarding modelling of the sintering deactivation process, even if the correct mechanism is chosen, deviations should be expected with the current state of knowledge due to several secondary parameters of Co supported catalysts that still have not been clarified. In particular, Co nanoparticles are, as commonly visualised by in situ XRD, composed by two intergrown crystalline phases (fcc and hcp) with a high population of stacking faults [38,69,70]. The contribution of the stacking faults and possible strain in the surface energy of the nanoparticles on catalytic behaviour is not yet understood.…”