Hydrodesulfurization of dibenzothiophene over siliceous MCM-41-supported nickel phosphide catalysts

A Facile Method to Synthesize Ni2P Catalysts and their Catalytic Performances in Hydrotreating Reactions

The bulk and supported Ni2P catalysts (Ni2P/γ-Al2O3 and Ni2P/MCM-41) were facile prepared by using nickel metal as nickel source via thermal treatment of hypophosphite in a separated reactor. The thermal decomposition behaviors of sodium hypophosphite were studied by online mass spectra. The effects of atmosphere, temperature, reaction time, and P/Ni atomic ratio on the as-prepared Ni2P catalysts were investigated. The Ni2P catalysts can also be obtained by using NiCl2 as nickel source but not for NiO. Since the nickel source is nickel metal and Ni2P catalysts were prepared in a separated reactor, the as-prepared Ni2P catalysts from Ni0 can be directly used without further purification, but the as-synthesized Ni2P catalyst from NiCl2 source should be further treated to remove the residues (such as Cl–) before use. As the active species for hydrodenitrogenation (HDN), Ni2P shows much higher activity than Ni0. For hydrodearomatization (HDA), Ni2P/MCM-41 shows much lower activity than Ni/MCM-41 but much better resistance to S-containing compounds in hydrogenation of naphthalene. The mechanism for synthesizing Ni2P catalysts with this facile method is proposed by online mass spectra.

Simultaneous HDS of DBT and 4,6-DMDBT over single-pot Ti-SBA-15-NiMo catalysts: influence of Si/Ti ratio on the structural properties, dispersion and catalytic activity

Influence of Si/Ti ratios on structural properties and HDS activity of DBT and DMDBT is investigated. New structural HDS catalyst is formed with TiO₂ phases predominates at Si/Ti = 1. DDS rate is enhanced by Ti addition while HYD rate remain almost constant.

Facile electrochemical synthesis of single crystalline CeO2 octahedrons and their optical properties

We developed a simple electrochemical process for the large-scale fabrication of single crystalline CeO(2) octahedrons and nanospheres from DMSO aqueous solution. The octahedrons with some structural defects have a size ranging from 200 to 300 nm. Moreover, highly crystalline CeO(2) nanospheres were also obtained via this electrochemical process based on the oriented attachment mechanism. The absorption edge of octahedrons and spheres shows a red-shift, and that of the octahedrons was near the visible region.