In-situ surface and gas phase analysis for kinetic studies under transient conditions The catalytic hydrogenation of CO2

Marwood, Michel; Doepper, R.; Renken, Albert

doi:10.1016/s0926-860x(96)00267-0

Cited by 255 publications

(173 citation statements)

References 31 publications

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“…Also the direct decomposition of carbonates has been proposed in this process, resulting in the possible formation of CO besides from CO 2 , which then followed the reaction pathway of the methanation of CO to yield methane [41]. However, no observance of CO(ads) in our study suggested that the CO 2 methanation reaction pathway over NiWMgO x involved the hydrogenation of carbonates species into formate species other than the direct decomposition of carbonates [42,43]. Similar reaction pathway has also been reported for Pd-Mg/SiO 2 [11], NiUSY zeolites [34] and Ni/Ce 0.5 Zr 0.5 O 2 [36].…”

Section: In Situ Drifts Studymentioning

confidence: 61%

A novel W-doped Ni-Mg mixed oxide catalyst for CO2 methanation

Yan

Dai

et al. 2016

Applied Catalysis B: Environmental

185

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a b s t r a c tNovel Ni-W-Mg mixed oxide catalysts (NiWMgO x ) were prepared by homogeneous precipitation and attempted for the methanation of CO 2 . Adding W remarkably promoted the activity with improved stability, anti-CO-poisoning ability and resistance against coke formation compared to the undoped NiMgO x catalyst. The superior reactivity of monodentate formate towards hydrogenation than that of bidentate formate species was identified by DRIFTS analysis and the formation of more active monodentate formate species was indisputably facilitated by W additives, leading to the greatly enhanced catalytic activity. H 2 -TPR and CO 2 -TPD characterization showed that doping W increased the number of stable CO 2 adsorption sites and helped in anchoring the Ni sites as a result of strengthened Ni-Mg interaction, both of which were responsible for the enhanced CO 2 methanation activity and the improved resistance against sintering.

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Section: In Situ Drifts Studymentioning

confidence: 61%

A novel W-doped Ni-Mg mixed oxide catalyst for CO2 methanation

Yan

Dai

et al. 2016

Applied Catalysis B: Environmental

185

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“…1 6,7 . However, recent experimental and theoretical studies show that this reaction mechanism, particularly on surfaces of non-model catalysts, is not fully understood [27][28][29][30][31][32] . The RWGS reaction is believed to follow either of two mechanisms: the direct dissociation of CO 2 to CO via a CO 2 -ion (pathway 1 in Fig.…”

mentioning

confidence: 99%

Unravelling structure sensitivity in CO2 hydrogenation over nickel

et al. 2018

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T he reduction of CO 2 emissions into the Earth's atmosphere is gaining legislative importance in view of its impact on the climate [1][2][3][4][5] . Reduction of the harmful effect of these emissions through reclamation of CO 2 is made attractive because CO 2 can be a zero-or even negative-cost carbon feedstock 6,7 . The conversion of renewably produced hydrogen and CO 2 into methane, or synthetic natural gas, over Ni is a solution that combines the potential to reduce CO 2 emissions with a direct answer to the temporal mismatch in renewable electricity production capacity and demand [8][9][10][11][12][13][14][15][16][17] . Chemical energy storage in the form of hydrogen production by electrolysis is a relatively mature technology; however, the required costly infrastructure, and inefficiencies in distribution and storage deem it inconvenient for large-scale application in the near future. Point-source CO 2 hydrogenation to methane represents an alternative approach with higher energy density. Furthermore, methane is more easily liquefied and can be stored safely in large quantities through infrastructures that already exist 18,19 . Power-to-gas (in this case methane) is thus actively considered as being capable of balancing electric grid stability, which will allow us to increase the renewable energy supply 20 .The search for fossil fuel alternatives, and application of a process such as that described above can arguably be achieved only with the help of advances in catalysis and the closely related field of nanomaterials. Continuous efforts in both fields have allowed us to make increasingly smaller and catalytically more active (metal) particles. However, it is already known that making progressively smaller supported catalyst particles does not necessarily linearly correspond to higher catalytic activity [21][22][23] . This phenomenon, where not all atoms in a supported metal catalyst have the same activity, is called structure sensitivity and is often attributed to the distinctly different chemistries on different lattice planes for π -bond activation in CO 2 , or σ -bond activation in, for example H 2 dissociation and C-H propagation 21,24 . The availability of stepped (less coordinated) versus terrace (more coordinated) sites on the surface of supported catalyst nanoparticles obviously changes with particle size, and atomic geometries become particularly interesting below 2 nm where, for example, π -bond activation is believed to not be able to occur 21 . While particle-size effects have been extensively studied for CO hydrogenation over Co 23,25 , the understanding of such structure sensitivity effects for these critical smaller metal particle sizes is lacking as sub-2-nm particles prove difficult to synthesize for first-row transition metals (Co, Fe and Ni). However, a particle-size effect for CO 2 hydrogenation is much less well established 26 .Here, we used a unique set of SiO 2 -supported Ni nanoparticles with diameters ranging from 1 to 7 nm in size, and show not only the existence of a distinct pa...

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“…The equilibrium CO 2 conversion is reached at 340 • C. CO 2 -TPD profiles of Ni/CZ show weak and medium sites, different from Ni/Al 2 O 3 , which shows weak and strong basic sites; CO 2 adsorbed on strong basic sites cannot desorb from Ni/Al 2 O 3 surface until 700 • C. Consequently, the strongly adsorbed CO 2 on the surface does not participate in the reaction carried out from 220 • C to 400 • C. According to [166], CO 2 reacts with surface hydroxyls and surface oxygen to form hydrogen and monodentate carbonate, respectively [164,[166][167][168][169][170][171][172]. Formate species could be also important intermediates during the reaction [63,173,174].…”

Section: Silica-supported Nickelmentioning

confidence: 99%

Supported Catalysts for CO2 Methanation: A Review

et al. 2017

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CO 2 methanation is a well-known reaction that is of interest as a capture and storage (CCS) process and as a renewable energy storage system based on a power-to-gas conversion process by substitute or synthetic natural gas (SNG) production. Integrating water electrolysis and CO 2 methanation is a highly effective way to store energy produced by renewables sources. The conversion of electricity into methane takes place via two steps: hydrogen is produced by electrolysis and converted to methane by CO 2 methanation. The effectiveness and efficiency of power-to-gas plants strongly depend on the CO 2 methanation process. For this reason, research on CO 2 methanation has intensified over the last 10 years. The rise of active, selective, and stable catalysts is the core of the CO 2 methanation process. Novel, heterogeneous catalysts have been tested and tuned such that the CO 2 methanation process increases their productivity. The present work aims to give a critical overview of CO 2 methanation catalyst production and research carried out in the last 50 years. The fundamentals of reaction mechanism, catalyst deactivation, and catalyst promoters, as well as a discussion of current and future developments in CO 2 methanation, are also included.

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In-situ surface and gas phase analysis for kinetic studies under transient conditions The catalytic hydrogenation of CO2

Cited by 255 publications

References 31 publications

A novel W-doped Ni-Mg mixed oxide catalyst for CO2 methanation

A novel W-doped Ni-Mg mixed oxide catalyst for CO2 methanation

Unravelling structure sensitivity in CO2 hydrogenation over nickel

Supported Catalysts for CO2 Methanation: A Review

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