Catalytic properties of nickel molybdenum sulphides supported on nickel and magnesium aluminates

Abstract

The hydrodesulphurization (HDS) of thiophene at atmospheric pressure, hydrodenitrogenation (HDN) of 2,6 diethylaniline (DEA) and of 1,2,3,4 tetrahydroquinoline (THQ) at 70 atm in a dynamic flow microreactor - these molecules being present alone or mixed in the feed - and finally HDN of mixtures of quinoline (Q) at 70 atm or of phenanthridine (Ph) at 140 atm with DEA in a batch reactor were the test reactions used to compare the performances of (Ni)MoS catalysts supported on MgAl 2O 4 and NiAl 2O 4 with a classical NiMoS/γ Al 2O 3 commercial catalyst. Some of the catalysts supported on NiAl 2O 4 appeared to be superior to the commercial one, whereas those supported on MgAl 2O 4 were found to be less active. HDS of thiophene, as well as the amount of carbon monoxide adsorbed at 0°C by sulphided catalysts permitted the prediction of the order of HDN activity of the catalysts for the conversion of some nitrogen-containing molecules. A strong inhibiting effect of molecules like Q, THQ or Ph (or some of their products formed during the process) on the HDN of DEA has been found and attributed to the competitive adsorption of these molecules on the supported active phase.