Infrared and x-ray photoelectron spectroscopy study of carbon monoxide and carbon dioxide on platinum/ceria

Jin, Tuo; Zhou, Yansong; Mains, Gilbert J.; White, J. M.

doi:10.1021/j100307a023

Cited by 230 publications

(145 citation statements)

References 2 publications

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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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Section: Silica-supported Nickelmentioning

confidence: 99%

Supported Catalysts for CO2 Methanation: A Review

et al. 2017

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“…In experimental studies using IR and X-ray photoelectron spectroscopy the presence of bent carbonate species on CeO 2 upon CO 2 adsorption has been observed 31 suggesting the CeO 2 surface to react as Lewis base in the CO 2 adsorption process. Theoretical evidence from DFT calculations on the adsorption processes on CeO 2 , however, is rare.…”

Section: Introductionmentioning

confidence: 99%

Coverage Effect of the CO₂ Adsorption Mechanisms on CeO₂(111) by First Principles Analysis

et al. 2013

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The adsorption of carbon dioxide on CeO2(111) has been studied using density functional theory. At low coverage (1/9 monolayer), CO2 is found to preferably adsorb in a monodentate configuration forming a carbonate species with a surface O atom. In this configuration, the CO2 molecule is bent with an O-C-O angle of 129 degrees and a remarkable elongation (to 1.27 angstrom) of the C-O bond length compared to the gas phase molecule, indicating a high degree of CO2 activation. A similar activation is observed when the CO2 molecule adsorbs as bidentate carbonate; however, this configuration is less stable. Linear configurations are found to adsorb very weakly at low coverage by physisorption. Increasing the coverage leads to a decrease of the stability of mono-and bidentate configurations which can be attributed to repulsive interactions between adjacent adsorbates and the limited capacity of the CeO2(111) surface to donate electrons to the adsorbates. In contrast, the binding energy of linearly adsorbed CO2 is shown to be coverage independent. At coverages >1/4 monolayer, we have also addressed the stability of mixed configurations where monodentate, bidentate, and linear species are present simultaneously on the surface. The most stable configurations are found when 1/3 monolayer CO2 is bound as monodentate species, and additional molecules are physisorbed forming partial layers of linear species. Analysis of the projected density of states has shown that the orbitals of linear species in the first partial layer lie at lower energies than the ones of the second partial layer suggesting stabilization of the former through interactions with preadsorbed monodentate species. These findings provide fundamental insight into the CO2 adsorption mechanism on CeO2 and potentially assist the design of new Ce-based materials for CO2 catalysis. ABSTRACTThe adsorption of carbon dioxide on CeO 2 (111) has been studied using density functional theory.At low coverage (1/9 monolayer), CO 2 is found to preferably adsorb in a monodentate configuration forming a carbonate species with a surface O atom. In this configuration, the CO 2 molecule is bent with a O-C-O angle of 129° and a remarkable elongation (to 1.27 Å) of the C-O bond length compared to the gas phase molecule, indicating a high degree of CO 2 activation. A similar activation is observed when the CO 2 molecule adsorbs as bidentate carbonate, however, this configuration is less stable. Linear configurations are found to adsorb very weakly at low coverage by physisorption. Increasing the coverage leads to a decrease of the stability of monoand bidentate configurations which can be attributed to repulsive interactions between adjacent adsorbates and the limited capacity of the CeO 2 (111) surface to donate electrons to the adsorbates. In contrast, the binding energy of linearly adsorbed CO 2 is shown to be coverage independent. At coverages >1/4 monolayer, we have also addressed the stability of mixed configurations where mono-, bidentate and linear species are pre...

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“…Adsorption of CO on ceria supported catalysts leads to accumulation of different carboxylate, carbonate and formate species on the ceria surface as revealed from infrared spectroscopic studies [32][33][34][35][36][37]. The oxidation state of ceria was also studied after different pretreatments by XPS [38,39,40].…”

Section: Introductionmentioning

confidence: 99%

Preferential CO oxidation in hydrogen (PROX) on ceria-supported catalysts, part I: Oxidation state and surface species on Pt/CeO2 under reaction conditions

Pozdnyakova

Teschner

Wootsch

et al. 2006

Journal of Catalysis

393

245

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The CO content of hydrogen feed to proton exchange membrane fuel cells (PEMFC) must be kept under 1-100 ppm for their proper operation. This can be achieved by using catalysts able to selectively oxidize CO in the presence of excess hydrogen (PROX). The present study reports on the mechanism of PROX reaction on Pt/CeO 2 catalyst, by using catalytic tests, in-situ DRIFTS, high-pressure XPS, HRTEM and TDS techniques. Bulk metallic, pronounced adsorbate-induced surface Pt and a small amount of oxidized Pt sites were detected by in-situ, high pressure XPS under PROX conditions. The pre-oxidized ceria surface was strongly reduced in pure H 2 but significantly re-oxidized under PROX conditions (i.e. O 2 +CO in excess hydrogen) at T=358 K. The remaining small amount of Ce 3+ decreased with increasing temperature. HRTEM found well-crystallized CeO 2 particles (8-10 nm) in the case of activated (pre-oxidized) sample that transformed in a large extent to an oxygen deficient ceria super-cell structure after PROX reaction. Metallic Pt particles (2-3 nm) and small (0.5-0.6 nm) Pt clusters were found by HRTEM. These findings were in accordance with the variations in relative intensity of the corresponding Pt-CO bands (DRIFTS). Different types of carbonate and formate species were detected (XPS and DRIFTS). Their possible role in the reaction mechanism is discussed. Resolved OH bands could not be found by DRIFT in the PROX reaction mixture indicating significant amount of adsorbed water in a hydrogen-bonded structure. Its presence seems to suppress hydrogen oxidation while CO oxidation still takes place, as the metallic particles are covered by CO (DRIFTS). The direct contribution of surface water in a low-temperature water-gas-shift (LTWGS) type reaction in the PROX mixture is proposed.

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Infrared and x-ray photoelectron spectroscopy study of carbon monoxide and carbon dioxide on platinum/ceria

Cited by 230 publications

References 2 publications

Supported Catalysts for CO2 Methanation: A Review

Supported Catalysts for CO2 Methanation: A Review

Coverage Effect of the CO₂ Adsorption Mechanisms on CeO₂(111) by First Principles Analysis

Preferential CO oxidation in hydrogen (PROX) on ceria-supported catalysts, part I: Oxidation state and surface species on Pt/CeO2 under reaction conditions

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Infrared and x-ray photoelectron spectroscopy study of carbon monoxide and carbon dioxide on platinum/ceria

Cited by 230 publications

References 2 publications

Supported Catalysts for CO2 Methanation: A Review

Supported Catalysts for CO2 Methanation: A Review

Coverage Effect of the CO2 Adsorption Mechanisms on CeO2(111) by First Principles Analysis

Preferential CO oxidation in hydrogen (PROX) on ceria-supported catalysts, part I: Oxidation state and surface species on Pt/CeO2 under reaction conditions

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Coverage Effect of the CO₂ Adsorption Mechanisms on CeO₂(111) by First Principles Analysis