Effect of Calcination Temperature on Mg-Al Layered Double Hydroxides (LDH) as Promising Catalysts in Oxidative Dehydrogenation of Ethanol to Acetaldehyde

Pinthong, Piriya; Praserthdam, Piyasan; Jongsomjit, Bunjerd

doi:10.5650/jos.ess18177

Cited by 25 publications

(19 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An important topic with respect to catalysts for ethanol dehydrogenation is the significant deactivation that occurs due to coke formation on the catalyst surface and the sintering of the active catalyst particles. This was found in the case of PdZn nanoparticles [28], monometallic Cu [29,30], bi-or tri-metallic Cu alloys [29,[31][32][33], SiO 2 − supported Cu catalysts [34] and V/Mg − Al catalysts [35,36]. There is a considerable number of papers that use computational methods such as density functional theory or a combination of experimental methods and modelling tools to investigate correlations between catalyst activity and selectivity on the one hand and material characteristics such as crystal faces, monolayer coverages, etc., on the other [37][38][39][40][41].…”

Section: N2 Sorptionmentioning

confidence: 57%

Ethanol Dehydrogenation: A Reaction Path Study by Means of Temporal Analysis of Products

et al. 2020

View full text Add to dashboard Cite

Conventional fossil fuels such as gasoline or diesel should be substituted in the future by environmentally-friendly alternatives in order to reduce emissions in the transport sector and thus mitigate global warming. In this regard, iso-butanol is very promising as its chemical and physical properties are very similar to those of gasoline. Therefore, ongoing research deals with the development of catalytically-supported synthesis routes to iso-butanol, starting from renewably-generated methanol. This research has already revealed that the dehydrogenation of ethanol plays an important role in the reaction sequence from methanol to iso-butanol. To improve the fundamental understanding of the ethanol dehydrogenation step, the Temporal Analysis of Products (TAP) methodology was applied to illuminate that the catalysts used, Pt/C, Ir/C and Cu/C, are very active in ethanol adsorption. H2 and acetaldehyde are formed on the catalyst surfaces, with the latter quickly decomposing into CO and CH4 under the given reaction conditions. Based on the TAP results, this paper proposes a reaction scheme for ethanol dehydrogenation and acetaldehyde decomposition on the respective catalysts. The samples are characterized by means of N2 sorption and Scanning Transmission Electron Microscopy (STEM).

show abstract

Section: N2 Sorptionmentioning

confidence: 57%

Ethanol Dehydrogenation: A Reaction Path Study by Means of Temporal Analysis of Products

et al. 2020

View full text Add to dashboard Cite

show abstract

“…30 The CO 2 desorption peak of the catalyst shifts to lower temperatures with a low peak area, indicating that the calcination temperature has a significant effect on the strong and medium-strong basic sites of the catalysts. 31 For the catalyst calcined at 400 and 500 °C, two CO 2 desorption peaks appeared at 300 and 400 °C, while the CO 2 -TPD curve of the calcined product at 500 °C shows that there is another desorption peak at more than 800 °C belonging to the strong base site. This indicates that the number of strong basic sites in the catalyst has a significant effect on its catalytic activity, and a catalyst with more moderately strong basic sites can have greater AN yield, thus showing a relationship between the basic properties and the catalytic activity for this base-catalyzed methylation.…”

Section: Chemical Adsorption Characterizationmentioning

confidence: 89%

Highly active Mg–Al hydrotalcite for efficient O‐methylation of phenol with DMC based on soft colloidal templates

Tang

Slaný

Yang

et al. 2021

J of Chemical Tech & Biotech

View full text Add to dashboard Cite

BACKGROUND: Anisole (AN) is an important compound that has been studied in research into antioxidants, plastic stabilizers, pesticides and dyes. One of the technological alternatives to synthesizing them is using a modified solid catalyst with a soft colloidal template. Synthesis of AN has been demonstrated using dimethyl carbonate (DMC) and phenol over a mixed oxide catalyst derived from Mg-Al hydrotalcite, employing cetyl trimethylammonium bromide (CTAB) as a soft colloidal template. RESULTS: When the reaction was performed at atmospheric pressure in the presence of catalyst (in an amount of 4.5 wt% with respect to the reactants, DMC and phenol) at 200 °C, and a DMC:phenol molar ratio of 2:1 for 8 h, good results were seen for both phenol conversion and selectivity of AN (87.66% and 99.38%, respectively). The yield of AN was 87.11%. CONCLUSION:The characterization of the catalyst demonstrated that the calcination temperature has a significant effect on the structure of the obtained Mg-Al hydrotalcite. Its surface properties and pore diameter distribution resulted in an increased concentration of hierarchical basic sites within the material. Weak and moderate basic sites contributed to the high conversion of phenol and good selectivity of AN. In addition, the thermal stability analysis of the as-prepared Mg-Al mixed oxide showed that the hierarchical structures can be preserved up to 500 °C and eventually be transformed into highly dispersed MgO particles.

show abstract

“…The Mg-Al hydrotalcite was synthesized by co-precipitation method as described in our previous study 22 . The obtained hydrotalcite powder was calcined at 450 in air for 6 h to form Mg-Al mixed oxide.…”

Section: Catalyst Preparationmentioning

confidence: 99%

“…The catalytic activity of all catalysts was investigated by the previous reported procedure 22 . The catalyst 0.05 g was placed over quartz wool bed 0.01 g in the continuous fixed-bed glass reactor with I.D.…”

Section: Reaction Studymentioning

confidence: 99%

Oxidative Dehydrogenation of Ethanol over Vanadium- and Molybdenum-modified Mg-Al Mixed Oxide Derived from Hydrotalcite

2019

Self Cite

View full text Add to dashboard Cite

Hydrotalcite or Mg-Al LDHs were synthesized by co-precipitation method. The Mg-Al mixed oxide was then derived by calcination of hydrotalcite at 450℃. The metal modified catalysts (Mo/Mg-Al and V/Mg-Al) were prepared by incipient wetness impregnation method. The obtained catalysts were characterized by several useful techniques and tested the reactivity for dehydrogenation and oxidative dehydrogenation of ethanol (gas-phase) to produce acetaldehyde. The catalytic reactions were performed at temperature range from 200 to 400℃ for both non-oxidative and oxidative atmospheres. The results showed that the vanadium-modified hydrotalcite (V/Mg-Al) exhibited the highest ethanol conversion (34.3%) and acetaldehyde yield (15.5%) at 400℃ in the non-oxidative atmosphere. For the oxidative dehydrogenation of ethanol, the V/Mg-Al catalyst showed the highest activity at 400℃ giving the ethanol conversion and acetaldehyde yield of 73.7% and 29.5%, respectively. This result probably related to the highest base density of V/Mg-Al catalyst (6.13 µmol CO 2 /m 2) measured by CO 2-TPD. The catalytic activity of Mg-Al catalyst and metal modified catalyst slightly decreased upon time-on-stream test for 10 h on oxidative dehydrogenation of ethanol due to carbon deposition.

show abstract

Effect of Calcination Temperature on Mg-Al Layered Double Hydroxides (LDH) as Promising Catalysts in Oxidative Dehydrogenation of Ethanol to Acetaldehyde

Cited by 25 publications

References 30 publications

Ethanol Dehydrogenation: A Reaction Path Study by Means of Temporal Analysis of Products

Ethanol Dehydrogenation: A Reaction Path Study by Means of Temporal Analysis of Products

Highly active Mg–Al hydrotalcite for efficient O‐methylation of phenol with DMC based on soft colloidal templates

Oxidative Dehydrogenation of Ethanol over Vanadium- and Molybdenum-modified Mg-Al Mixed Oxide Derived from Hydrotalcite

Contact Info

Product

Resources

About