Heterogeneous catalysis with metal nitrides

Hargreaves, J. S. J.

doi:10.1016/j.ccr.2012.10.005

Cited by 146 publications

(103 citation statements)

References 198 publications

Supporting

Mentioning

102

Contrasting

Order By: Relevance

“…The modification observed in the XRD pattern at high R cannot be easily attributed to a given phase but such synthesis conditions clearly favours nitride formation. Indeed, among the diverse synthesis routes leading to nitrides, high temperature treatment of iron precursors under NH3 or under a N2/H2 mixture is widespread [25]. In our case, higher concentration of NH3 provides a more nitriding atmosphere and also increases the temperature through CO2 laser absorption.…”

Section: Tracking the Nature Of The Iron Phasesmentioning

confidence: 85%

Synthesis and Characterization of Carbon/Nitrogen/Iron Based Nanoparticles by Laser Pyrolysis as Non-Noble Metal Electrocatalysts for Oxygen Reduction

Pérez

Jorda

Bonville

et al. 2018

View full text Add to dashboard Cite

This paper reports original results on the synthesis of Carbon/Nitrogen/Iron-based Oxygen Reduction Reaction (ORR) electrocatalysts by CO 2 laser pyrolysis. Precursors consisted of two different liquid mixtures containing FeOOH nanoparticles or iron III acetylacetonate as iron precursors, being fed to the reactor as an aerosol of liquid droplets. Carbon and nitrogen were brought by pyridine or a mixture of pyridine and ethanol depending on the iron precursor involved. The use of ammonia as laser energy transfer agent also provided a potential nitrogen source. For each liquid precursor mixture, several syntheses were conducted through the step-by-step modification of NH 3 flow volume fraction, so-called R parameter. We found that various feature such as the synthesis production yield or the nanomaterial iron and carbon content, showed identical trends as a function of R for each liquid precursor mixture. The obtained nanomaterials consisted in composite nanostructures in which iron based nanoparticles are, to varying degrees, encapsulated by a presumably nitrogen doped carbon shell. Combining X-ray diffraction and Mossbauer spectroscopy with acid leaching treatment and extensive XPS surface analysis allowed the difficult question of the nature of the formed iron phases to be addressed. Besides metal and carbide iron phases, data suggest the formation of iron nitride phase at high R values. Interestingly, electrochemical measurements reveal that the higher R the higher the onset potential for the ORR, what suggests the need of iron-nitride phase existence for the formation of active sites towards the ORR.

show abstract

Section: Tracking the Nature Of The Iron Phasesmentioning

confidence: 85%

Synthesis and Characterization of Carbon/Nitrogen/Iron Based Nanoparticles by Laser Pyrolysis as Non-Noble Metal Electrocatalysts for Oxygen Reduction

Pérez

Jorda

Bonville

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Rhenium nitride was prepared by ammonolysis of NH 4 ReO 4 (Sigma Aldrich, 99.5 %) at 350°C for 2 h. A temperature ramp rate of 5°C min -1 was applied. Cobalt rhenium nitride was prepared by ammonolysis of a cobalt rhenium oxide precursor at 700°C for 3 h. A temperature ramp rate of 5°C min -1 was applied.…”

Section: Methodsmentioning

confidence: 99%

“…The sample was passivated as detailed above. The precursor was prepared by incipient wetness impregnation of NH 4 ReO 4 with Co(NO 3 ) 2 .6H 2 O (Sigma Aldrich, 98? %) to yield a Co/Re ratio of 1/4.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

The Denitridation of Nitrides of Iron, Cobalt and Rhenium Under Hydrogen

2013

View full text Add to dashboard Cite

The denitridation behaviour of binary iron, cobalt and rehnium nitrides under H 2 /Ar has been investigated. The iron nitride was found to lose over 70 % of its as prepared nitrogen content at 400°C. The cobalt nitride was completely denitrided at 250°C. Rhenium nitride lost close to 90 % of its nitrogen at 350°C. In addition, Co-Re 4 prepared by ammonolyis was investigated, whilst only traces of NH 3 were lost from this material under H 2 /Ar at 400°C, with H 2 /N 2 it proved to be an active ambient pressure ammonia synthesis catalyst in accordance with previous literature.

show abstract

“…Transition metal nitrides have attracted considerable attention as heterogeneous catalysts for numerous reactions [1]. Among them, vanadium nitride, which is an interstitial compound, has been shown to be an active catalyst for synthesis and decomposition of ammonia [2][3][4][5].…”

Section: Introductionmentioning

confidence: 99%