Dry reforming of methane over gallium-based supported catalytically active liquid metal solutions.
Moritz WolfAna Luiza de OliveiraNicola TaccardiSven MaiselMartina HellerSharmin Khan AntaraAlexander SøgaardPeter FelferAndreas GörlingMarco HaumannPeter WasserscheidPublished in: Communications chemistry (2023)
Gallium-rich supported catalytically active liquid metal solutions (SCALMS) were recently introduced as a new way towards heterogeneous single atom catalysis. SCALMS were demonstrated to exhibit a certain resistance against coking during the dehydrogenation of alkanes using Ga-rich alloys of noble metals. Here, the conceptual catalytic application of SCALMS in dry reforming of methane (DRM) is tested with non-noble metal (Co, Cu, Fe, Ni) atoms in the gallium-rich liquid alloy. This study introduces SCALMS to high-temperature applications and an oxidative reaction environment. Most catalysts were shown to undergo severe oxidation during DRM, while Ga-Ni SCALMS retained a certain level of activity. This observation is explained by a kinetically controlled redox process, namely oxidation to gallium oxide species and re-reduction via H 2 activation over Ni. Consequentially, this redox process can be shifted to the metallic side when using increasing concentrations of Ni in Ga, which strongly suppresses coke formation. Density-functional theory (DFT) based ab initio molecular dynamics (AIMD) simulations were performed to confirm the increased availability of Ni at the liquid alloy-gas interface. However, leaching of gallium via the formation of volatile oxidic species during the hypothesised redox cycles was identified indicating a critical instability of Ga-Ni SCALMS for prolonged test durations.
Keyphrases
- molecular dynamics
- density functional theory
- pet ct
- metal organic framework
- transition metal
- electron transfer
- ionic liquid
- high temperature
- hydrogen peroxide
- carbon dioxide
- signaling pathway
- anaerobic digestion
- room temperature
- mass spectrometry
- climate change
- visible light
- health risk
- human health
- genetic diversity
- drug induced