H2 purification through preferential oxidation of CO over ceria supported bimetallic Au-based catalysts

Fiorenza, Roberto; Crisafulli, C.; Scirè, Salvatore

doi:10.1016/j.ijhydene.2016.05.114

Cited by 26 publications

(32 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This happens also for selectivity to CO 2 ( Figure 1c). To comprehend this behavior, the fact that cerium oxide has a strong tendency to provide active oxygens with strong oxidation power [6,12,25,26], which are however reactive towards both CO and H 2 , must be taken into account. This causes a drop of selectivity at higher temperature due to the higher activation energy of H 2 oxidation compared to that of CO [27][28][29][30].…”

Section: Catalytic Activitymentioning

confidence: 99%

“…In the case of the Ru/CeO 2 -CuO catalyst, CO conversion shifted to a higher temperature, probably due to the fact that Cu catalysts require higher temperatures to promote the CO oxidation [12,13,25]. However, it cannot be fully ruled out that the low activity of the Ru/CeO 2 -CuO catalyst can be related to an unsuitable pretreatment of the CuO-CeO 2 system, for which calcination at 450 • C (adopted here for all samples) could not be ideal for the formation of the active Cu + sites [19,20].…”

Section: Catalytic Activitymentioning

confidence: 99%

“…It must be stressed that the increased activity of the Ru-Pd system cannot be related to the concentration of the metal species, which on both mono and bimetallic samples remains 1 wt % (0.5-0.5% on bimetallics and 1% on monometallics). It has been seen that bimetallics can be often better performing than the related monometallics due to a synergy between the two metals and/or the support [6,12,31]. …”

Section: Catalytic Activitymentioning

confidence: 99%

“…Therefore, the catalyst of this process must be highly selective towards the first reaction. Noble-metal catalysts, such as Pd [8], Rh [9], Ru [10,11], Au [12][13][14] and Pt [15,16], have revealed good CO-PROX performance. The selection of the proper support has been also found crucial in addressing the catalytic activity.…”

Section: Introductionmentioning

confidence: 99%

“…The selection of the proper support has been also found crucial in addressing the catalytic activity. Recently, the use of a reducible/active support, such as cerium oxide or iron oxide, resulted in remarkably low-temperature CO-PROX activities [12,17]. The peculiar red-ox properties of CeO 2 involving the facile exchange between Ce 3+ and Ce 4+ states and the high mobility of O 2-ions in the lattice, are the key factors to explain the high relevance of this oxide as a metal support in the PROX reaction [6,12,13,18].…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Ru–Pd Bimetallic Catalysts Supported on CeO2-MnOX Oxides as Efficient Systems for H2 Purification through CO Preferential Oxidation

et al. 2018

Self Cite

View full text Add to dashboard Cite

Abstract:The catalytic performances of Ru/ceria-based catalysts in the CO preferential oxidation (CO-PROX) reaction are discussed here. Specifically, the effect of the addition of different oxides to Ru/CeO 2 has been assessed. The Ru/CeO 2 -MnO x system showed the best performance in the 80-120 • C temperature range, advantageous for polymer-electrolyte membrane fuel cell (PEMFC) applications. Furthermore, the influence of the addition of different metals to this mixed oxide system has been evaluated. The bimetallic Ru-Pd/CeO 2 -MnO x catalyst exhibited the highest yield to CO 2 (75%) at 120 • C whereas the monometallic Ru/CeO 2 -MnO x sample was that one with the highest CO 2 yield (60%) at 100 • C. The characterization data (H 2 -temperature programmed reduction (H 2 -TPR), X-ray diffraction (XRD), N 2 adsorption-desorption, diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), X-ray photoelectron spectroscopy (XPS)) pointed out that the co-presence of manganese oxide and ruthenium enhances the mobility/reactivity of surface ceria oxygens accounting for the good CO-PROX performance of this system. Reducible oxides as CeO 2 and MnO x , in fact, play two important functions, namely weakening the CO adsorption on the metal active sites and providing additional sites for adsorption/activation of O 2 , thus changing the mechanism from competitive Langmuir-Hinshelwood into non-competitive one-step dual site Langmuir-Hinshelwood/Mars-van Krevelen. As confirmed by H 2 -TPR and XPS measurements, these features are boosted by the simultaneous presence of ruthenium and palladium. The strong reciprocal interaction of these metals between them and with the CeO 2 -MnO x support was assumed to be responsible of the promoted reducibility/reactivity of CeO 2 oxygens, thus resulting in the best CO-PROX efficiency at low temperature of the Ru-Pd/CeO 2 -MnO x catalyst. The higher selectivity to CO 2 found on the Ru-Pd system, which reduces the undesired H 2 consumption, represents a promising result of this research, being one of the key aims of the design of CO-PROX catalysts.

show abstract

Section: Catalytic Activitymentioning

confidence: 99%

Section: Catalytic Activitymentioning

confidence: 99%

Section: Catalytic Activitymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Ru–Pd Bimetallic Catalysts Supported on CeO2-MnOX Oxides as Efficient Systems for H2 Purification through CO Preferential Oxidation

et al. 2018

Self Cite

View full text Add to dashboard Cite

show abstract

Influence of the Hydrothermal Parameters on the Physicochemical Characteristics of Cu−Ce Oxide Nanostructures

Kappis

2019

ChemCatChem

View full text Add to dashboard Cite

A series of highly active and selective CuCeO x catalysts was prepared via appropriate tuning of the parameters (concentration, temperature) of a citrates-hydrothermal method. The obtained catalysts were characterized by various physicochemical techniques such as (in-situ) X-ray diffraction (XRD), N 2 adsorption-desorption, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), while preferential oxidation of CO (CO-PROX) in H 2 -rich stream was used as probe reaction. Suitable modification of the hydrothermal parameters resulted in catalysts with remarkable performance in CO-PROX reaction, which was strongly dependent on the concentration of oxygen vacancies and reduced copper species.

show abstract

Carbon supported bimetallic Ru-Co catalysts for H₂ production through NaBH₄ and NH₃ BH₃ hydrolysis

2017

Self Cite

View full text Add to dashboard Cite

Summary This work investigates the effect of the addition of small amounts of Ru (0.5‐1 wt%) to carbon supported Co (10 wt%) catalysts towards both NaBH4 and NH3BH3 hydrolysis for H2 production. In the sodium borohydride hydrolysis, the activity of Ru‐Co/carbon catalysts was sensibly higher than the sum of the activities of corresponding monometallic samples, whereas for the ammonia borane hydrolysis, the positive effect of Ru‐Co systems with regard to catalytic activity was less evident. The performances of Ru‐Co bimetallic catalysts correlated with the occurrence of an interaction between Ru and Co species resulting in the formation of smaller ruthenium and cobalt oxide particles with a more homogeneous dispersion on the carbon support. It was proposed that Ru°, formed during the reduction step of the Ru‐Co catalysts, favors the H2 activation, thus enhancing the reduction degree of the cobalt precursor and the number of Co nucleation centers. A subsequent reduction of cobalt and ruthenium species also occurs in the hydride reaction medium, and therefore the state of the catalyst before the catalytic experiment determines the state of the active phase formed in situ. The different relative reactivity of the Ru and Co active species towards the two investigated reactions accounted for the different behavior towards NaBH4 and NH3BH3 hydrolysis.

show abstract

H2 purification through preferential oxidation of CO over ceria supported bimetallic Au-based catalysts

Cited by 26 publications

References 42 publications

Ru–Pd Bimetallic Catalysts Supported on CeO2-MnOX Oxides as Efficient Systems for H2 Purification through CO Preferential Oxidation

Ru–Pd Bimetallic Catalysts Supported on CeO2-MnOX Oxides as Efficient Systems for H2 Purification through CO Preferential Oxidation

Influence of the Hydrothermal Parameters on the Physicochemical Characteristics of Cu−Ce Oxide Nanostructures

Carbon supported bimetallic Ru-Co catalysts for H₂ production through NaBH₄ and NH₃ BH₃ hydrolysis

Contact Info

Product

Resources

About

H2 purification through preferential oxidation of CO over ceria supported bimetallic Au-based catalysts

Cited by 26 publications

References 42 publications

Ru–Pd Bimetallic Catalysts Supported on CeO2-MnOX Oxides as Efficient Systems for H2 Purification through CO Preferential Oxidation

Ru–Pd Bimetallic Catalysts Supported on CeO2-MnOX Oxides as Efficient Systems for H2 Purification through CO Preferential Oxidation

Influence of the Hydrothermal Parameters on the Physicochemical Characteristics of Cu−Ce Oxide Nanostructures

Carbon supported bimetallic Ru-Co catalysts for H2 production through NaBH4 and NH3 BH3 hydrolysis

Contact Info

Product

Resources

About

Carbon supported bimetallic Ru-Co catalysts for H₂ production through NaBH₄ and NH₃ BH₃ hydrolysis