Enhancing the anisole hydrodeoxygenation activity over Ni/Nb₂O_5−xby tuning the oxophilicity of the support

Abstract

The present work focuses on designing a robust non-noble metal-based niobia-supported catalyst with a high number of oxygen vacancies for an efficient HDO activity of anisole. Various synthesis procedures, such...

Fine-Tuning of Ni/NiO over H-NbOx for Enhanced Eugenol Hydrogenation through Enhanced Oxygen Vacancies and Synergistic Participation of Active Sites

“…The binding energies of 204.8 and 207.5 eV correspond to Nb 3d 5/2 and Nb 3d 3/2 for H-NbO x (Figure a), and the decrease in binding energy compared to that of Nb 2 O 5 suggests the change in the electronic environment resulting from the lattice deformation of Nb 2 O 5 after NaOH and HCl treatment. This alteration in the electronic environment created more oxygen vacancies in H-NbO x , which will modulate the active sites . Similarly, the binding energies at 205.6 and 208.4 eV correspond to Nb 3d 5/2 and Nb 3d 3/2 for 10Ni/H-NbO x (Figure a).…”

“…The H 2 -desorption peak from Nb 2 O 5 and H-NbO x was observed between 400–550 and 400–650 °C, respectively, indicating the adsorption of H 2 on the bare supports. Nb 2 O 5 and NbO x , having oxygen vacancies, are known to adsorb H 2 via homolytic or heterolytic cleavage. , The 10 wt % Ni-supported H-NbO x (10Ni/H-NbO x ) showed a desorption between 300 and 400 °C, attributed to weakly adsorbed H 2 on the Ni NPs, and another prominent desorption between 550 and 650 °C, indicating strong hydrogen adsorption over Ni. , Similarly, for 10Ni/Nb 2 O 5 , the desorption peak was observed between 350 and 500 °C, corresponding to weakly adsorbed H 2 , while less-prominent desorption characteristics were observed between 450 and 500 °C, indicating lower contents of strongly adsorbed H 2 . 10NiO/H-NbO x was evaluated for hydrogen adsorption and the desorption peak was found at 450–600 °C, indicating the strongly adsorbed hydrogen (Figure S6).…”

“…A reduction peak between 450 and 600 °C was also obtained. It could be due to the hydrogen spillover from the Ni to H-NbO x support, providing evidence for the Ni NPs over H-NbO x and an electronic synergy between Ni/NiO and H-NbO x . , The adsorption of hydrogen on the catalyst surface is crucial in facilitating hydrogenation, and therefore, the amount of adsorbed hydrogen was quantified by H 2 -TPD analysis (Figure b, Table ). The H 2 -desorption peak from Nb 2 O 5 and H-NbO x was observed between 400–550 and 400–650 °C, respectively, indicating the adsorption of H 2 on the bare supports.…”

“…An H 2 -TPR analysis was performed to confirm the presence of NiO. The 38,44 The adsorption of hydrogen on the catalyst surface is crucial in facilitating hydrogenation, and therefore, the amount of adsorbed hydrogen was quantified by H 2 -TPD analysis (Figure 6b, Table 1). The H 2 -desorption peak from Nb 2 O 5 and H-NbO x was observed between 400−550 and 400−650 °C, respectively, indicating the adsorption of H 2 on the bare supports.…”

“…Recently, the reducible properties and oxygen storage capacity of niobium oxide have attracted considerable attention as it provided strong metalsupport interaction and facilitated decorating metals with tunable oxidation states, affecting catalytic activity. 37,38 Niobium oxide has been extensively investigated for various applications, and metal-decorated Nb 2 O 5 has also been evaluated due to its strong metal-support interactions. 39−41 Therefore, modification of the niobium oxide properties and utilization in hydrogenation reaction is of significant interest.…”