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X Demographics
Mendeley readers
Attention Score in Context
| Title |
Vapor-Phase Hydrogenation of Levulinic Acid to γ-Valerolactone Over Bi-Functional Ni/HZSM-5 Catalyst
|
|---|---|
| Published in |
Frontiers in Chemistry, July 2018
|
| DOI | 10.3389/fchem.2018.00285 |
| Pubmed ID | |
| Authors |
Margarita Popova, Petar Djinović, Alenka Ristić, Hristina Lazarova, Goran Dražić, Albin Pintar, Alina M. Balu, Nataša Novak Tušar |
| Abstract |
The hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) in vapor-phase is economically more viable route if compared to reaction in liquid-phase. To improve the GVL yield in the vapor-phase reaction, the optimization of nickel modified zeolite as bi-functional catalyst (Ni/HZSM-5) was studied. Ni/HZSM-5 materials with fixed Al/Si molar ratio of 0.04 and different nominal Ni/Si molar ratios (from 0.01 to 0.05) were synthesized without the use of organic template and with the most affordable sources of silica and alumina. Materials were characterized by X-ray powder diffraction, SEM-EDX, TEM-EDX, pyridine TPD and DRIFTS, H2-TPR, N2 physisorption and isoelectric point. In the synthesized materials, 61-83% of nickel is present as bulk NiO and increases with nickel content. Additionally, in all catalysts, a small fraction of Ni2+ which strongly interacts with the zeolite support was detected (10-18%), as well as Ni2+ acting as charge compensating cations for Brønsted acid sites (7-21%). Increasing the nickel content in the catalysts leads to a progressive decrease of Brønsted acid sites (BAS) and concomitant increase of Lewis acid sites (LAS). When BAS/LAS is approaching to 1 and at the same time the amount of NiO reducible active sites is around 80%, the bi-functional Ni/HZSM-5-3 catalyst (Ni/Al = 0.59) leads to 99% conversion of LA and 100% selectivity to GVL at 320°C. This catalyst also shows stable levulinic acid hydrogenation to GVL in 3 reaction cycles conducted at 320°C. The concerted action of the following active sites in the catalyst is a key element for its optimized performance: (1) Ni metallic active sites with hydrogenation effect, (2) Lewis acid sites with dehydration effect, and (3) nickel aluminate sites with synergetic and stabilizing effects of all active sites in the catalyst. |
X Demographics
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Switzerland | 1 | 100% |
Demographic breakdown
| Type | Count | As % |
|---|---|---|
| Scientists | 1 | 100% |
Mendeley readers
The data shown below were compiled from readership statistics for 82 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Unknown | 82 | 100% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Student > Ph. D. Student | 15 | 18% |
| Researcher | 11 | 13% |
| Student > Bachelor | 7 | 9% |
| Student > Master | 6 | 7% |
| Student > Doctoral Student | 5 | 6% |
| Other | 13 | 16% |
| Unknown | 25 | 30% |
| Readers by discipline | Count | As % |
|---|---|---|
| Chemical Engineering | 18 | 22% |
| Chemistry | 17 | 21% |
| Engineering | 7 | 9% |
| Agricultural and Biological Sciences | 3 | 4% |
| Biochemistry, Genetics and Molecular Biology | 3 | 4% |
| Other | 7 | 9% |
| Unknown | 27 | 33% |
Attention Score in Context
This research output has an Altmetric Attention Score of 1. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 17 July 2018.
All research outputs
#18,643,992
of 23,096,849 outputs
Outputs from Frontiers in Chemistry
#2,238
of 6,040 outputs
Outputs of similar age
#229,543
of 296,625 outputs
Outputs of similar age from Frontiers in Chemistry
#79
of 181 outputs
Altmetric has tracked 23,096,849 research outputs across all sources so far. This one is in the 11th percentile – i.e., 11% of other outputs scored the same or lower than it.
So far Altmetric has tracked 6,040 research outputs from this source. They receive a mean Attention Score of 2.0. This one has gotten more attention than average, scoring higher than 51% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 296,625 tracked outputs that were published within six weeks on either side of this one in any source. This one is in the 12th percentile – i.e., 12% of its contemporaries scored the same or lower than it.
We're also able to compare this research output to 181 others from the same source and published within six weeks on either side of this one. This one is in the 37th percentile – i.e., 37% of its contemporaries scored the same or lower than it.