Highly dispersed and ultra-small Ni nanoparticles over hydroxyapatite for hydrogenation of levulinic acid

Autor: N. Pethan Rajan, V.R. Chary Komandur, Shaik Syed Hussain, Bhanuchander Ponnala, Ramu Kuna, Putrakumar Balla
Rok vydání: 2021
Předmět:
Zdroj: Reaction Kinetics, Mechanisms and Catalysis. 135:183-199
ISSN: 1878-5204
1878-5190
Popis: Hydroxyapatite (HAp) supported nickel catalysts were synthesised via simple urea precipitation method with various nickel loadings ranging from 5 to 20 wt% and tested in vapour phase hydrogenation of levulinic acid (LA) under ambient pressure. The as-prepared catalysts were systematically characterized by using X-ray diffraction, UV-DRS, HR-TEM, SEM, BET surface area, TPR and TPD-CO2 techniques. The active nickel surface area and the Ni dispersion over the HAp support were measured by using H2 chemisorption method. The XRD results confirmed that the nickel oxide particles were well dispersed over HAp support at lower loadings and NiO crystallites were formed at higher loadings. The HR-TEM images revealed that ultra small (2.49 ± 0.4 nm) and homogenously distributed nickel nanoparticles are formed over 5 wt% NiHAp catalyst. Moreover, UV-DRS analysis is also confirmed the similar phenomena. The H2-TPR analysis revealed that the presence of strong interaction between nickel particles and hydroxyapatite support was observed. Among several HAp supported Ni catalysts tested in this study, we found that 5 wt% NiHAp catalyst is the most active and selective due to the presence of high number of active surface Ni particles over HAp support and this was confirmed by the H2 chemisorption analysis and HR-TEM.
Databáze: OpenAIRE
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