Synergy Effects of Cobalt Oxides on Ni/Co-Embedded Al2O3 for Hydrogen-Rich Syngas Production by Steam Reforming of Propane

Abstract

The synergetic effects of Co oxides on the Ni/CoAl (NCA) catalysts were observed at an optimal molar ratio of Al/Co = 2 (NCA(2)) due to the partial formations of thermally stable spinel CoAl2O4 phases for the steam reforming of propane (SRP). The optimal content of the spinel CoAl2O4 phases on the NCA(2) was responsible for the formation of the relatively active oxophilic metallic Co nanoparticles with a smaller amount of less active NiAl2O4 on the surfaces by preserving the relative amount of metallic Co of 68% and 52% in the reduced and used catalysts, which enhanced the catalytic activity and stability with the largest specific rate of 1.37 C3H8/(Ni + Co)h−1 among the tested NCA catalysts. The larger or smaller amounts of Co metal on the less active NCA mainly caused the preferential formation of larger aggregated Ni nanoparticles ~16 nm in size due to their weaker interactions, or induced the smaller formations of active metal phases by selectively forming the spinel NiAl2O4 phases with ~60% in the NCA(4), resulting in a fast deactivation.

Enhanced coke-resistant Co-modified Ni/modified alumina catalyst for the bireforming of methane

“…A higher distribution of active metal leads to a stronger interaction and hence shifts the reduction peak to a higher reduction temperature region. 35 Another reason for the peak broadness is due to the collective formation of metal-aluminate species under higher calcination temperature, 31,36 and the results are concurrent with the XRD results. The hydrogen consumption is shown in Table 2.…”

Pure Ni-Based and Trimetallic Ni-Co-Fe Catalysts for the Dry Reforming of Methane: Effect of K Promoter and the Calcination Temperature

“…Based on other studies, the reduction of alumina supported nickel-based catalysts to metallic nickel occurs at temperatures < 600 °C [21,22]. Supporting this, our results demonstrated that the which may form as a result of the interaction of the metals with the alumina support [23,24]. CO 2 -TPD analysis was carried out to identify the number of basic sites present on the oxidized catalysts (Fig.…”

Efficient spinel iron-cobalt oxide/nitrogen-doped ordered mesoporous carbon catalyst for rechargeable zinc-air batteries

“…The average diameters of the metal oxide particles are 3.5, 7.5, 13.7, 15.1 and 17.5 nm for Fe/NOMC, Fe2Co/NOMC, FeCo/NOMC, Fe0.5Co/NOMC, and Co/NOMC, respectively. Therefore, the incorporation of cobalt dramatically increases the particle size of the metal oxide, as discovered previously [39,40] S7. The elemental compositions were quantified and are listed in Table 1.…”