Promoting Effect of TiO₂on the Hydrodenitrogenation Performance of Nickel Phosphide

Abstract

TiO 2 -containing bulk Ni 2 P catalysts (Ti x -Ni 2 P) were prepared by coprecipitation and in situ H 2 temperatureprogrammed reduction (TPR), and characterized by XRD, CO chemisorption, TEM, XPS, TPR, and NH 3 -TPD. Their hydrodenitrogenation performances were studied by using quinoline and decahydroquinoline (DHQ) as the model molecules. Both the hydrogenation and C-N bond cleavage activities of Ni 2 P were improved by the introduction of TiO 2 . The TiO 2 species were mainly located separately on the surface of the catalysts and had strong interactions with surface Ni and P species. The reducibility of the precursors as well as the surface electronic properties of Ni 2 P catalysts were affected by the addition of TiO 2 . Ti x -Ni 2 P showed higher CO uptake but less acid sites than Ni 2 P. The promoting effect of TiO 2 was discussed by considering the electronic interactions between surface Ti and Ni 2 P species and changes in the adsorption geometries of quinoline, DHQ, as well as the partially hydrogenated intermediates over Ti x -Ni 2 P.

Preparation of Ni 2 P/Al 2 O 3 by temperature-programmed reduction of a phosphate precursor with a low P/Ni ratio

“…Nitrogen physisorption was performed on a Quantachrome Autosorb-1-MP analyzer. CO adsorption was measured using pulsed chemisorption as described elsewhere [19]. 27 Al MAS NMR spectra of the Al 2 O 3 supports were taken on an Agilent DD2 500 MHz NMR spectrometer.…”

Hydrodesulfurization of Dibenzothiophene and its Hydrogenated Intermediates Over Bulk Ni2P

“…Prior to HDS reaction, the precursor was transformed into bulk Ni 2 P by an in situ H 2 TPR method [25]. It was reduced in a 200 mL/min H 2 flow by heating quickly from room temperature to 120°C and keeping this temperature for 1 h, then heated to 400°C at 5°C/min and holding at 400°C for 1 h, and finally heated at 2.5°C/min to 500°C and holding at 500°C for 3 h. The surface area (measured on a Micromeritics Tristar II 3020 apparatus) and the CO uptake (determined as described elsewhere [26]) of the prepared Ni 2 P were 4.3 m 2 /g and 5.0 lmol/g, respectively.…”

Review of Denitrogenation of Algae Biocrude Produced by Hydrothermal Liquefaction

“…Therefore, we investigated the HDN of these compounds with various catalysts, focusing primarily on the HDN of quinoline, which we selected as the model compound. It is well documented that some phosphides exhibit catalytic activity in the HDN of quinoline, such as Ni 2 P [93,94], MoP [95], and Ni-rich bimetallic phosphides [96,97], which were typically modified with a metallic oxide, such as TiO 2 and CeO 2 . HDN is performed at high temperatures and high pressures with these catalysts and an abundance of the desired product propylcyclohexane has been produced.…”