Development of Co Supported on Co−Al Spinel Catalysts from Exsolution of Amorphous Co−Al Oxides for Carbon Dioxide Reforming of Methane

Abstract

In this study, redox exsolution method was used to synthesize Co/Co−Al spinel for dry reforming. The aim is to improve metal‐support interaction, which enhances the catalyst's stability and minimizes carbon deposition. The synthesized catalysts were observed as Co embedded on Co deficient CoAl2O4‐like spinel (denoted as Co−Al spinel). The reduction temperature was optimized at 750 °C. Investigations on the effect of Co loading revealed that optimum Co loading is needed to control the Co particle size, providing balance between limiting carbon deposition rate and preventing dissolution of Co into the support. The best performing catalyst, Co‐15, in which the molar ratio of Co and Al is 15 : 85 produced a stable 81.5 % and 87.4 % conversions for CH4 and CO2 continuously over 24 h of reaction time with 13.51 wt% of carbon deposition. The strong metal‐support interaction of Co and Co−Al spinel in Co‐15 stabilizes and prevents the sintering of Co particles, enhancing the efficiency for dry reforming reaction.

Adsorption of CO2 on Terrace, Step, and Defect Sites on Pt Surfaces: A Combined TPD, XPS, and DFT Study

“…a The dispersion (C 6 ) coefficient and van der Waals radius for the Pt atom are not in ref 55, so they were determined using the approach proposed by Grimme, 56 in which the ionization potential and static dipole polarizability of an atom is derived with the PBE0 functional. 71 The calculated C 6 coefficient and van der Waals radius were 83.90 J•nm 6 •mol −1 and 1.810 Å, respectively (1455.272223891 Hartree/Bohr 6 and 3.420405649 Bohr, respectively).…”

“…In the industry, CO 2 is hydrogenated into methanol and/or long-chain hydrocarbons on metal catalysts . Moreover, it is used in dry reforming of methane to produce syngas for Fischer–Tropsch synthesis. − In these complex processes, interactions with active metals play an important role in activation of chemically inert CO 2 . Typically, the first elementary step in these reaction processes is adsorption of CO 2 .…”

Boosting methane partial oxidation on ceria through exsolution of robust Ru nanoparticles

“…The fact that the nanoparticles are socketed into the oxide surface imparts beneficial effects in terms of stability, avoiding nanoparticle sintering 23 . For that reason, exsolution has gained considerable attention in the field of solid oxide fuel cells and electrolyzers 24,25 , and more recently its application has been found to be promising in methane reforming reactions [26][27][28][29] . For instance, Kousi and co-workers obtained Ni exsolved and submerged nanoparticles on La 0.8 Ce 0.1 Ni 0.4 Ti 0.6 O 3 with synergistically enhance the oxygen supply capacity.…”

Coking-resistant dry reforming of methane over Ni/γ-Al2O3 catalysts by rationally steering metal-support interaction

“…Deduced from the results of H 2 -TPR and relevant tests (Figures S10-S14), the bounded Ni would gradually exsolute to replenish active sites for DRM during the reaction at high temperature (750 C) (Wong et al, 2019). It would make it difficult to distinguish the differences between the bounded Ni and the free state ) was much lower compared to the former two samples.…”