In Power-to-Methane (PtM) plants, the renewable electricity supply can be stabilized by using green electrons to produce H 2 via H 2 O electrolysis, which is subsequently used to hydrogenate CO 2 into CH 4 . In this work PtM is studied in a cascade fashion, from simulated solar light to methane production in an all-inone setup, which was newly developed for this work. This setup was used to assess the effects of H 2 stream purity on the activity of Ni/SiO 2 catalysts in CO 2 methanation. An activity effect in downstream methanation is shown to be onset by aerosols that evolve from the electrochemical splitting of water. Small amounts of K are shown to affect CH 4 production positively, but only if they are deposited in situ, via KOH aerosols. K-doped Ni/ SiO 2 catalysts prepared in an ex situ manner, by impregnation with a KOH solution, showed a decrease in activity, while the same amount of KOH was deposited. Operando FT-IR spectroscopy reveals that increased back-donation to CO-containing intermediates and carbonates formation likely causes catalyst deactivation in ex situ samples as often reported in literature for Ni/SiO 2 catalysts. The mechanism for in situ promotion is either an increased rate in the hydrogenation of CH x (X = 0-3) fragments, or a more facile water formation or desorption as CO-containing reaction intermediates are unaffected by in situ promotion. These results are relevant to PtM from a fundamental standpoint explaining the effect of potassium on nickel methanation, but also from a practical standpoint as the presented effect of in situ promotion is difficult to achieve via standard synthesis methods.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.