Role of Iron on the Structure and Stability of Ni 3.2 Fe/Al 2 O 3 during Dynamic CO 2 Methanation for P2X Applications

Support effect on Ni-based mono- and bimetallic catalysts in CO2 hydrogenation

Aiming at a comprehensive understanding of support effects on Ni-based bimetallic catalyst for CO2 hydrogenation, spectroscopy (DRIFTS) with CO as a probe molecule and temperature-programmed techniques were used to investigate the impact of different supports (MgO, CeO2, ZrO2) on Ni- and Ni,Fe catalysts. Kinetic parameters revealed that the higher selectivity to methanation for Ni and Ni,Fe supported on the reducible oxides (CeO2, ZrO2) is due to the inhibition of reverse water-gas shift reaction (RWGS) by hydrogen. A promoting effect of Fe on Ni was only observed on MgO-supported catalysts. In situ DRIFTS with CO adsorption showed different electronic properties of Ni sites with partially reduced oxide (i.e. ZrO2 and CeO2). H2-TPR and CO2-TPD confirmed the significant role of metal-support interaction (MSI) in CeO2-supported catalysts for CO2 activation. The MSI between Ni/Ni,Fe and reducible supports are crucial for catalytic performance, ultimately leading to the higher activity and stability in CO2 hydrogenation.

Novel high-pressure/high-temperature reactor cell for in situ and operando x-ray absorption spectroscopy studies of heterogeneous catalysts at synchrotron facilities

This paper presents the development of a novel high-pressure/high-temperature reactor cell dedicated to the characterization of catalysts using synchrotron x-ray absorption spectroscopy under operando conditions. The design of the vitreous carbon reactor allows its use as a plug-flow reactor, monitoring catalyst samples in a powder form with a continuous gas flow at high-temperature (up to 1000 °C) and under high pressure (up to 1000 bar) conditions, depending on the gas environment. The high-pressure/high-temperature reactor cell incorporates an automated gas distribution system and offers the capability to operate in both transmission and fluorescence detection modes. The operando x-ray absorption spectroscopy results obtained on a bimetallic InCo catalyst during CO2 hydrogenation reaction at 300 °C and 50 bar are presented, replicating the conditions of a conventional microreactor. The complete setup is available for users and permanently installed on the Collaborating Research Groups French Absorption spectroscopy beamline in Material and Environmental (CRG-FAME) sciences and French Absorption spectroscopy beamline in Material and Environmental sciences at ultra-high dilution (FAME-UHD) beamlines (BM30 and BM16) at the European Synchrotron Radiation Facility in Grenoble, France.

Synchrotron PXRD deconvolutes nickel particle and support changes in Ni/ZrO2 methanation catalysts

Operando synchrotron powder X-ray diffraction deconvolutes support and metal nanoparticle changes during thermal deactivation of Ni/ZrO2 methanation catalysts.

Bimetallic Ni-Based Catalysts for CO2 Methanation: A Review

CO₂ methanation has recently emerged as a process that targets the reduction in anthropogenic CO₂ emissions, via the conversion of CO₂ captured from point and mobile sources, as well as H₂ produced from renewables into CH₄. Ni, among the early transition metals, as well as Ru and Rh, among the noble metals, have been known to be among the most active methanation catalysts, with Ni being favoured due to its low cost and high natural abundance. However, insufficient low-temperature activity, low dispersion and reducibility, as well as nanoparticle sintering are some of the main drawbacks when using Ni-based catalysts. Such problems can be partly overcome via the introduction of a second transition metal (e.g., Fe, Co) or a noble metal (e.g., Ru, Rh, Pt, Pd and Re) in Ni-based catalysts. Through Ni-M alloy formation, or the intricate synergy between two adjacent metallic phases, new high-performing and low-cost methanation catalysts can be obtained. This review summarizes and critically discusses recent progress made in the field of bimetallic Ni-M (M = Fe, Co, Cu, Ru, Rh, Pt, Pd, Re)-based catalyst development for the CO₂ methanation reaction.

Promising Catalytic Systems for CO2 Hydrogenation into CH4: A Review of Recent Studies

The increasing utilization of renewable sources for electricity production turns CO2 methanation into a key process in the future energy context, as this reaction allows storing the temporary renewable electricity surplus in the natural gas network (Power-to-Gas). This kind of chemical reaction requires the use of a catalyst and thus it has gained the attention of many researchers thriving to achieve active, selective and stable materials in a remarkable number of studies. The existing papers published in literature in the past few years about CO2 methanation tackled the catalysts composition and their related performances and mechanisms, which served as a basis for researchers to further extend their in-depth investigations in the reported systems. In summary, the focus was mainly in the enhancement of the synthesized materials that involved the active metal phase (i.e., boosting its dispersion), the different types of solid supports, and the frequent addition of a second metal oxide (usually behaving as a promoter). The current manuscript aims in recapping a huge number of trials and is divided based on the support nature: SiO2, Al2O3, CeO2, ZrO2, MgO, hydrotalcites, carbons and zeolites, and proposes the main properties to be kept for obtaining highly efficient carbon dioxide methanation catalysts.

Structural dynamics in Ni–Fe catalysts during CO2 methanation – role of iron oxide clusters

Operando XAS coupled with MES supported by DFT unravel the highly dynamic nature of Ni–Fe catalysts during CO₂ methanation and beneficial formation of iron oxide clusters.

Bridging the gap between industry and synchrotron: an operando study at 30 bar over 300 h during Fischer–Tropsch synthesis

Long-term operando spectroscopic study of a Fischer–Tropsch catalyst at a synchrotron radiation facility under realistic conditions with full product analysis.