NANOSTRUCTURED SULFIDE SYNTHESIS TYPE BIMETALLIC NiMoSxCy IN THE PRENSENCE OF STRUCTURE DIRECTING AGENTS AND THEIR ACTIVITY IN HDS

Abstract

With a view to reducing the sulfur content in diesel fuels, were synthesized bimetallic catalysts novel NiMo catalysts, supported and unsupported, using structure-directing agents. The above mentioned materials were modified during the protocol of calcinations, in order to obtain nanostructured systems. All catalysts were characterized using several techniques CHNS-O, ICP-OES, TEM, SEM, EDX, N2  adsorption–desorption isotherms (BET), XRD, XPS, DLS and RAMAN. The presences of CTAB, as structure-directing agents, lead to nanostructured materials, with size of particle between 5 y 50 nm. The produced materials are hybrid NiMoSxCy the high surface area, which when they are subject to a “soft” oxydation leads to obtain nanostructured with minimum of sinterization. The catalytic activity of all substrates in HDS`s reaction, was determined in a flow fixed bed reactor at three temperatures 320, 360 y 400 °C, 40 bar of pressures of H2, WHSV = 39 h-1 and 3h for reaction time. The feedstock for HDS´s reaction was prepared considering “the matrix effect”, so that is was constituted by paraffin’s (60%), olefins (30%), and aromatic hydrocarbons (10%), and sulfur compounds (470 ppm). These last compounds constituted by very refractory species present in the fuel diesel as DBT (100 ppm) and 4,6-DMDBT (100 ppm). All the synthesized materials presented activity in the HDS reaction of (400 °C, 3h), conversions being reaching high conversions, favoring the least refractory DBT substrates.