Effect of Phosphine Doping and the Surface Metal State of Ni on the Catalytic Performance of Ni/Al2O3 Catalyst

Abstract

Ni-based catalysts as replacement for noble metal catalysts are of particular interest in the catalytic conversion of biomass due to their cheap and satisfactory catalytic activity. The Ni/SiO2 catalyst has been studied for the hydrogenolysis of glycerol, and doping with phosphorus (P) found to improve the catalytic performance significantly because of the formation of Ni2P alloys. However, in the present work we disclose a different catalytic phenomenon for the P-doped Ni/Al2O3 catalyst. We found that doping with P has a significant effect on the state of the active Ni species, and thus improves the selectivity to 1,2-propanediol (1,2-PDO) significantly in the hydrogenolysis of glycerol, although Ni-P alloys were not observed in our catalytic system. The structure and selectivity correlations were determined from the experimental data, combining the results of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), hydrogen temperature-programmed reduction (H2-TPR) and ammonia temperature-programmed desorption (NH3-TPD). The presence of NiO species, formed from P-doped Ni/Al2O3 catalyst, was shown to benefit the formation of 1,2-PDO. This was supported by the results of the Ni/Al2O3 catalyst containing NiO species with incomplete reduction. Furthermore, the OPEN ACCESSCatalysts 2015, 5 760 role the NiO species played in the reaction and the potential reaction mechanism over the P-doped Ni/Al2O3 catalyst is discussed. The new findings in the present work open a new vision for Ni catalysis and will benefit researchers in designing Ni-based catalysts.

Aqueous‐Phase Hydrodeoxygenation of Biomass Sugar Alcohol into Renewable Alkanes over a Carbon‐Supported Ruthenium with Phosphoric Acid Catalytic System

“…reported that the conversion of isosorbide and mono‐oxygenated intermediates was identified as the slowest reaction step . Moreover, the production of C 5 species might be because of the decarboxylation or decarbonylation of oxygenate groups at the ends of the carbon chains …”

“…Among the alkane products, the selectivity for C 5 /C 6 alkane was approximately 50 %, which is lower than that of the Ru/C+H 3 PO 4 catalytic system. Interestingly, the long‐chain alkane selectivity increased gradually with an increase of the reaction temperature (Figure S8) and reached 74.8 % at 573 K, which could be because of the decomposition of phosphate additives at high reaction temperatures . Moreover, HDO experiments over Ru/C with mineral acids were performed to investigate the role of phosphoric acid.…”

“…The experimental set‐up (Figure S10) of the aqueous HDO reaction by using a trickle‐bed reactor has been described previously . During the reaction, sorbitol solution (20 wt %) was pumped into the reactor at a flow rate of 0.05 mL min −1 by using a high‐pressure liquid pump (HPLP).…”

Metal Catalysts Recycling and Heterogeneous/Homogeneous Catalysis

“…They explain that electron transfer between active Ru species and SnOx additives modifies the adsorption of the nitro group of the substrate, influencing the product selectivity, and also improves the stability of the catalysts. Li et al [7] report the catalytic performance of phosphorus-doped Ni/Al2O3 catalysts for the hydrogenolysis of a biomass-derived compound of glycerol. These are recyclable and selective catalysts for the production of 1, 2-propanediol.…”

Hydrotreating Activity of Co-Mo/Al2O3 Promoted with Boron and Phosphorous

“…Many group [10] indicate that the addition of phosphorus promotes solubility of molybdate due to the formation of complexes phosphomolybdate, which simulates the preparation of the catalyst. García-Vila et al [11] and Li et al [12] indicated that the addition of phosphorus improves the surface Al 2 O 3 which consumes OH groups of Al 2 O 3 .…”