Key Role of Precursor Nature in Phase Composition of Supported Molybdenum Carbides and Nitrides

Tišler, Zdeněk; Velvarská, Romana; Skuhrovcová, Lenka; Pelíšková, Lenka; Akhmetzyanova, Uliana

doi:10.3390/ma12030415

Cited by 14 publications

(11 citation statements)

References 69 publications

(83 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There are some studies concerning the alkaline activation of natural zeolites, but not in terms of materials or the study of their properties for use in catalytic and sorption applications. These materials have great potential as it has been proven in a number of national patents and also in our earlier publications [32][33][34]. Currently, research is going on and the materials or catalysts prepared from them are tested for catalytic decomposition of N 2 O (Co catalysts), deoxygenation of oils, and condensates from aldolization reactions (MoCx/MoNx catalysts), but also for heavy metal sorption applications.…”

Section: Influence Of Calcinationmentioning

confidence: 99%

Acid and Thermal Treatment of Alkali-Activated Zeolite Foams

et al. 2019

Self Cite

View full text Add to dashboard Cite

The foamed alkali-activated zeolite materials have been studied primarily in terms of mechanical and structural properties as potential substitutes for concrete and other building materials. However, they also have interesting textural and acid properties that make them much more useful, especially in the chemical industry. The aim of the study is to map in detail the influence of post-synthesis modifications of alkali-activated natural zeolite foams on their chemical, mechanical, and textural properties for possible use in catalytic and adsorption applications. Alkali-activated natural zeolite foam pellets were prepared by activation with mixed potassium hydroxide and sodium silicate activator and foamed using H2O2 solution. The foam pellets were post-synthetic modified by leaching with mineral and organic acids and calcination. The properties of the modified materials were characterised on the basis of XRF, XRD, N2 physisorption, DRIFT, SEM, NH3-TPD analyses, and the strength measurements. Our data showed that the basic clinoptilolite structure remains unchanged in the material which is stable up to 600 °C after acid leaching. In two-step leaching, the specific surface area increases to 350 m2/g and the leaching process allows the acid properties of the materials to be varied.

show abstract

Section: Influence Of Calcinationmentioning

confidence: 99%

Acid and Thermal Treatment of Alkali-Activated Zeolite Foams

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…The desired phase composition, surface properties and catalytic activity can be reached by varying the synthesis conditions, such as reactant gas (CH 4 , NH 3 , N 2 , etc. ), gas flow, precursor nature and temperature . However, as yet, very few studies have focused on the use of bulk molybdenum nitrides, carbides and phosphides in HDO and even fewer have determined the influence of their phase composition on catalytic activity.…”

Section: Introductionmentioning

confidence: 99%

“…), gas flow, precursor nature and temperature. [41] However, as yet, very few studies have focused on the use of bulk molybdenum nitrides, carbides and phosphides in HDO [24] and even fewer have determined the influence of their phase composition on catalytic activity.…”

Section: Introductionmentioning

confidence: 99%

Molybdenum Nitrides, Carbides and Phosphides as Highly Efficient Catalysts for the (hydro)Deoxygenation Reaction

et al. 2019

Self Cite

View full text Add to dashboard Cite

Transition metal nitrides, carbides and phosphides have the potential to replace the expensive and hazardous catalysts typically used for the conversion of fatty acids. However, there has been little research on the influence of treatment conditions and precursor nature on the properties of such catalytic systems. To better understand these dependencies, we synthesized a number of Mo catalysts by temperature‐programmed reduction (700‐900 °C; CH4/N2, N2/H2) using ammonium heptamolybdate, diammonium phosphate and hexamethylenetetramine (HMT) as Mo, C, N and P sources. The presence of HMT in the precursor mixtures ensured the synthesis of pure phase Mo2C, Mo2N and MoP. Catalytic activity in the (hydro)deoxygenation of stearic acid (240 min; 360 °C; 50 bar of H2) decreased in the following order: Mo2C>Mo2N>MoP. However, all of the studied Mo‐based catalysts showed good deoxygenation efficiency and, thus, represent excellent alternatives to traditional noble and sulfur‐containing catalysts.

show abstract

“…When FA is adsorbed on the acid site of the γ-Mo 2 N catalyst, the hydroxyl group of FA could be cleaved, and then the hydroxyl group could combine with the H impurity on the surface to form H 2 O. Thereafter, cleavage of H–C bonds to produce CO and compensation of H on the catalyst could be achieved, since γ-Mo 2 N possesses a Pt-like property, , with the H–C bond breakage ability for FA decomposition. − As such, the catalytic cycle could be completed by the release of CO and H 2 O.…”

Section: Results and Discussionmentioning

confidence: 99%

Formic Acid as a Bio-CO Carrier: Selective Dehydration with γ-Mo₂N Catalysts at Low Temperatures

Yoshida

Shi

et al. 2020

ACS Sustainable Chem. Eng.

View full text Add to dashboard Cite

Formic acid (FA) can be considered a bridge between biomass and green fuels, as biomass can be oxidized to FA, followed by FA dehydration to CO for Fischer–Tropsch synthesis. In this work, a series of γ-Mo2N-based catalysts used for FA dehydration was prepared by the facile pyrolysis of a Mo-containing precursor at different temperatures. It was found that the γ-Mo2N-based catalysts exhibited high performance for FA dehydration to CO with a maximum selectivity of ∼99.8%, and the onset reaction temperature over the γ-Mo2N-based catalysts was also much lower (100–200 °C) than those over conventional solid acid catalysts. In particular, the γ-Mo2N obtained at a pyrolysis temperature of 625 °C exhibited the highest activity, which was followed by those of the catalysts obtained at 600, 650, and 700 °C, which was consistent with the acidities of these catalysts. However, the CO selectivity monotonically increased with the increase in the catalyst preparation temperature but decreased with the increase in the FA decomposition temperature. FA conversion decreased when the contact time between the catalyst and the FA was reduced, but conversely, the CO selectivity increased. The enhanced CO selectivity might be ascribed to dehydrogenation having comparatively lower kinetics than that of dehydration, and thus, compared to dehydration, dehydrogenation could be more apparently suppressed by the reduced contact time, resulting in a higher CO selectivity. Moreover, it was found that the γ-Mo2N catalyst had no obvious deactivation for FA dehydration over the 20 h continuous operation period.

show abstract

Key Role of Precursor Nature in Phase Composition of Supported Molybdenum Carbides and Nitrides

Cited by 14 publications

References 69 publications

Acid and Thermal Treatment of Alkali-Activated Zeolite Foams

Acid and Thermal Treatment of Alkali-Activated Zeolite Foams

Molybdenum Nitrides, Carbides and Phosphides as Highly Efficient Catalysts for the (hydro)Deoxygenation Reaction

Formic Acid as a Bio-CO Carrier: Selective Dehydration with γ-Mo₂N Catalysts at Low Temperatures

Contact Info

Product

Resources

About

Key Role of Precursor Nature in Phase Composition of Supported Molybdenum Carbides and Nitrides

Cited by 14 publications

References 69 publications

Acid and Thermal Treatment of Alkali-Activated Zeolite Foams

Acid and Thermal Treatment of Alkali-Activated Zeolite Foams

Molybdenum Nitrides, Carbides and Phosphides as Highly Efficient Catalysts for the (hydro)Deoxygenation Reaction

Formic Acid as a Bio-CO Carrier: Selective Dehydration with γ-Mo2N Catalysts at Low Temperatures

Contact Info

Product

Resources

About

Formic Acid as a Bio-CO Carrier: Selective Dehydration with γ-Mo₂N Catalysts at Low Temperatures